Summary:
The marketing team needs to verify how personalized and dynamic content will appear to individual subscribers before sending a campaign. This requires a tool that can render the final, personalized email for specific subscribers or test profiles, accurately displaying Ampscript, personalization strings, and dynamic content logic. The goal is to catch errors and ensure the correct content is displayed for different audience segments.

Correct Option:

B. Subscriber Preview
This is the correct tool for this specific task. Subscriber Preview allows a user to enter a specific Subscriber Key or email address and see a fully rendered preview of the email exactly as that individual subscriber would receive it. It processes all personalization strings, dynamic content blocks, and Ampscript logic in real-time, providing the most accurate way to test rendering and content targeting before sending.

Incorrect Option:

A. Einstein Content Testing
This feature is used for A/B testing different subject lines or content variations to determine which one performs better with a live audience. It is an analytical tool for optimizing engagement after you have confirmed the emails render correctly. It does not provide a pre-send preview to validate personalization rendering for a specific subscriber.

C. Journey Builder System Optimization
This is not a feature for testing email content. It is a set of tools and reports used to monitor the health and performance of Journey Builder itself, such as checking for entry source limits or journey throughput. It is related to system administration and journey analytics, not pre-send content validation.

Reference:
Salesforce Marketing Cloud Email Studio Documentation

Summary:
The requirement is to implement an email send log for tracking and compliance, with the data export process already established. A send log is a record of all sending activity, and compliance often mandates retaining these records for a specific period to prove consent and sending practices. The key is to manage how long this historical data is stored within the Marketing Cloud platform before it is automatically purged.

Correct Option:

A. Data Retention
This setting is used to define a policy for how long records are stored in a Data Extension before being automatically deleted by the system. For a compliance-driven send log, you would set a specific retention period (e.g., 25 months) to meet legal requirements without manually managing the data. This ensures records are available for audit purposes for the required duration and are then purged to manage data volume.

Incorrect Option:

B. Data Relationships
This setting is used to create a filter or constraint between two Data Extensions, such as enforcing referential integrity. It is not used for managing the lifespan of data. For a send log, which is typically a standalone record of events, establishing a relationship with another Data Extension does not fulfill the core requirement of data retention for compliance.

C. Primary Key
A Primary Key is a field (or combination of fields) that uniquely identifies a single record in a Data Extension and enforces data integrity by preventing duplicates. While a send log must have a unique identifier (like a JobID and SubscriberID combination), defining the Primary Key is a structural step, not one that manages the tracking and compliance requirement of how long the data is kept.

Reference:
Salesforce Marketing Cloud Documentation

Summary 📝
The requirement is to proof an email with personalized content using a test data extension before the final send. The most direct and efficient method in Marketing Cloud Engagement is to use the Subscriber Preview feature to visualize the personalization for a specific test record, and then use the integrated Test Send feature. This process sends a personalized version of the email to the reviewer's inbox, allowing them to verify the content, links, and overall rendering as a genuine send, but without triggering the full campaign.

Correct Option ✅

B. Perform a Subscriber Preview and test send.
Subscriber Preview allows the associate to select a record from the test data extension to render the email exactly as that test subscriber would see it, including all personalized content.

The Test Send function, available from within the preview interface, allows the associate to send this specific, personalized version of the email directly to the reviewer's inbox.

This is the ideal method for proofing, as the reviewer sees the email rendered in their actual inbox with the dynamic data from the test record.

Incorrect Options ❌

A. Generate a Preview and send it to the reviewer.
While the Preview function renders the personalized content, there is no native feature to simply "send the preview" (i.e., forward the rendering screen). The standard method to get the personalized email to the reviewer is by using the Test Send option, which is included in option B.

C. Execute a Send flow using the test data extension.
Executing a full Send flow (like a User-Initiated Send or an Automation Send) is too drastic for a simple proofing step. This action initiates a live send job that uses sending functionality. While it would send the email, it complicates the process by requiring a full send configuration when a simple, non-production test send is sufficient and preferred.

Reference 🔗
Salesforce Help Documentation - Email Studio Preview and Test

Explanation:

The field Is Opted In represents a binary state: either the contact is opted in (1) or is not (0).
Marketing Cloud supports the Boolean data type for fields that store true/false or 1/0 values.
Using Boolean ensures:
Logical clarity (the field is clearly meant to represent a yes/no condition)
Efficient storage and processing
Compatibility with segmentation and decision splits in Journey Builder or Automation Studio

Let’s break down the other options:
A. Number
Stores numeric values
Technically valid, but semantically misleading — not ideal for binary logic
B. Boolean ✅
Stores true/false or 1/0 values
Best fit for binary opt-in status
C. Text
Stores string values
Inefficient and error-prone for binary logic (e.g., "1" vs "true" vs "yes")

Summary:
Marketing Cloud provides specific templates for creating Data Extensions that automatically collect and store different types of system-generated data. To gather information about individual email sends, you need a template that logs every sending event. While Data Views are system views that provide similar data, they are not permanent Data Extensions. The correct method to create a permanent, customizable Data Extension for this purpose is to use the Send Logging template, which is designed specifically for this use case.

Correct Option:

C. Send Logging:
This is a predefined Data Extension template. When you create a new Data Extension and select the "Send Logging" template, it generates a Data Extension with a schema designed to automatically capture a detailed log of every email sent. This includes information like JobID, SubscriberKey, EmailAddress, and SendTime, providing a persistent record of all send activity.

Incorrect Option:

A. Reports:
Reports are analytical outputs and dashboards built within the Reporting tab. They are not a type of Data Extension template. You cannot create a Data Extension to gather send data by selecting a "Reports" template, as this category does not exist for Data Extension creation.

B. Data View:
Data Views are system-owned, read-only views that provide a 6-month rolling window of data. While the _Sent Data View contains send information, it is not a template for creating a user-owned Data Extension. A Data Extension created from a template is a separate, user-managed object for storing data permanently.