Explanation:
Your answer is correct. The requirement is very specific: display multiple fields in a separate section at the top of the record page. The Highlights Panel is the standard, out-of-the-box component designed precisely for this purpose.

Let's evaluate each option:

A. Highlights Panel (Correct):
This is a standard Lightning component whose sole purpose is to display a high-density, compact list of key field values in a prominent position at the top of a record page. It is the ideal choice for showing critical information (like Amount, Close Date, Stage, etc.) without requiring the user to scroll. It can easily accommodate 12 fields in a clean, multi-column layout.

B. Path (Incorrect):
The Path component is a guided visual tool that helps users track a record's progress through a series of stages (like a sales process). While it is also placed at the top of the page, its function is to show the current stage and provide guidance, not to display a variety of different field values.

C. Custom Lightning Web Component (Incorrect):
While a developer could build a custom component to display 12 fields, this is unnecessary and inefficient. The platform already provides a perfectly suitable, configurable, and supported standard component for this exact need: the Highlights Panel. Using a custom component would be "re-inventing the wheel" and require development effort.

D. Accordion (Incorrect):
An Accordion is a component that allows you to collapse and expand sections of content to save space on the page. It is typically used further down the page in the main body. Placing 12 key fields inside an accordion at the top of the page would actually hide them from immediate view, which defeats the purpose of having them be prominently displayed "at the top."

References:
Salesforce Help: "Salesforce Lightning App Builder Guide" - Search for "Highlights Panel Component".
Trailhead: Look for modules or projects on "Lightning App Builder" which cover adding and configuring standard components like the Highlights Panel.

Explanation:
Your answer is correct. The core of the problem is user forgetfulness, and the goal is to automatically enforce the business process. Let's analyze each option.

C. Submit the record for approval from an automated process. (Correct):
This is the most direct and robust solution. You can use a Process Builder or a Flow that is triggered when an Opportunity is created or edited. The process would check the criteria (e.g., if the Closed Date is changed to a date more than 30 days in the future) and then use the "Submit for Approval" action to automatically start the approval process. This completely removes the reliance on the sales rep remembering to click a button, ensuring compliance.

A. Give the manager the "API Enabled" permission to permit approval responses by email. (Incorrect):
The "API Enabled" permission is for system integrations and has no bearing on a manager's ability to respond to an approval request via email. Managers can already approve records via email if the approval process is configured for email responses. This does nothing to solve the problem of the record not being submitted in the first place.

B. Use a validation rule and an email alert to the manager requesting approval. (Incorrect):
While this option identifies the problem (a validation rule can prevent saving the record with a future close date), it creates a poor user experience. It blocks the rep from saving their work and merely notifies the manager. The manager would then have to manually track down the rep and instruct them to submit for approval. It does not automatically enforce the process; it just creates an error and a notification.

D. Change the entry criteria on the approval process to criteria are met and lock the record on initial submission. (Incorrect):
This is a misunderstanding of how approval processes work. An approval process must be explicitly started by either a user manually submitting it or an automated process. Simply meeting the entry criteria does not automatically trigger the process. The "lock the record" setting applies after the process has started, not before.

Key Concept:
The fundamental principle here is automation vs. notification. When the goal is to guarantee a process runs, you must automate its initiation. Relying on users (reps or managers) to take manual action will lead to the process being skipped.

References:
Salesforce Help: "Start an Approval Process with a Flow" or "Start Approval Processes in Process Builder"

Explanation:
Your answer is correct. The key to this question lies in the phrase "created a sandbox template for Accounts, Projects, and Project Milestones." Let's break down why a Partial Copy sandbox is the necessary choice.

B. Partial Copy (Correct):
A Partial Copy sandbox is specifically designed for this scenario. It includes all of your org's metadata (like the flows, custom objects, and fields you are reconfiguring) and allows you to copy a subset of your standard and custom object data. Since the app builder has already defined a template specifying which records (from Accounts, Projects, and Milestones) to bring over, a Partial Copy sandbox is the only full-featured sandbox type that can fulfill this requirement for functional testing of flows with real data.

A. Developer Pro (Incorrect):
A Developer Pro sandbox is intended for development and testing in an environment that includes all metadata (like a Developer sandbox) but with slightly more storage. The critical limitation is that it does not include any standard or custom object data. Since the app builder needs to test flows with specific Account, Project, and Milestone records, a data-less Developer Pro sandbox is insufficient.

C. Developer (Incorrect):
A Developer sandbox is the most limited type. It copies all metadata but includes no standard or custom object data. It's perfect for coding and basic configuration tests but cannot be used to test functionality that depends on specific record data, as in this case.

D. Scratch Org (Incorrect):
A Scratch Org is a source-driven, temporary deployment environment for development and testing. While it can have sample data pushed to it, it is not populated by copying a specific subset of data from your production org using a sandbox template. Its purpose is for modern development lifecycle (DevOps) processes, not for creating a replica of a specific slice of production data for flow testing.

References:
Salesforce Help: "Sandbox Types and Templates"

Explanation:
Your answer is correct. Let's break down why Schema Builder is the ideal tool for this task and why the others are not.

D. Schema Builder (Correct):
This is the premier visual tool for exploring an org's data model. Its primary purpose is to display objects (both standard and custom) and the relationships between them (lookup, master-detail) as a dynamic, interconnected diagram. An app builder can easily drag objects onto the canvas and see all the relationships at a glance, making it perfect for getting a holistic understanding of how the entire system connects.

A. Fields & Relationships (Incorrect):
While you can view relationships here, you can only do it one object at a time. You would have to go to Object Manager -> select a specific object -> click "Fields & Relationships" to see a list of that single object's relationships. It is a detailed, textual view, not a holistic, visual one. It's inefficient for understanding the "big picture" of how all objects relate.

B. Object Manager (Incorrect):
The Object Manager is the central hub for managing all objects. You can see a list of every object, create new ones, and access their settings. However, it does not provide a visual diagram of the relationships between them. It's a list, not a map.

C. Lightning App Builder (Incorrect):
This tool is for building the user interface (UI) of Lightning pages (App Pages, Home Pages, Record Pages). It is used to add and configure components like related lists, but it is not used for viewing or understanding the underlying database relationships between objects.

References:
Salesforce Help: "View Objects and Fields with Schema Builder"
Trailhead: The "Data Modeling" module on Trailhead has a specific unit dedicated to using Schema Builder.

Explanation:

Your answer is correct. Here is a detailed breakdown of why.
When you create a master-detail relationship in Salesforce, the platform automatically treats the child object as a "detail" of the parent object in the context of reports. This has a direct and automatic impact on the available report types.

A. A Galaxy__c with Star__c report type will be automatically created. (Correct):
This is the standard platform behavior. For any master-detail relationship, Salesforce automatically generates a "Primary Object with Related Object" report type. In this case, since Galaxy__c is the master (parent) and Star__c is the detail (child), the system creates a report type called "Galaxies with Stars". This allows users to create reports that show Galaxy records, with a related list of their associated Star records.

B. A Star__c report type with Galaxy__c as a field will be automatically created. (Incorrect):
While a standard Star__c report type will exist and will include the Galaxy__c master-detail field, this is not the special, automatically created report type that the question is highlighting. The key automatic behavior is the creation of the parent-with-child report type, not just adding a field to the child's report.

C. A new custom report type will need to be created for Star__c with lookup fields from Galaxy__c. (Incorrect):
This is not necessary. The relationship is a master-detail, not a lookup, and the necessary report type is created automatically. No manual creation is required for basic reporting.

D. A new custom report type will need to be created for Galaxy__c with Star__c. (Incorrect):
This is the opposite of what happens. The platform automatically creates this for you. Manually creating a custom report type would be redundant.

Key Concept:
The defining characteristic of a master-detail relationship in reporting is the automatic creation of a "Primary Object with Related Object" report type. This is a major consideration when choosing between a master-detail and a lookup relationship.

References:

Salesforce Help: "How Report Types Are Determined"
This article explains that report types are automatically created for master-detail relationships.

Salesforce Help: "Master-Detail Relationship Considerations"
This documentation outlines all implications of creating a master-detail relationship, including its effect on reporting.