Explanation:

Declarative development uses point-and-click tools, while programmatic uses code. Key differences include setup, limits, and testing.

Correct Answers:

C. Declarative development can be done using the setup menu.
→ Configured via clicks (no code) in Salesforce Setup (e.g., Flows, Validation Rules).

D. Declarative development does not require Apex test classes.
→ Unlike Apex, no test coverage needed for deployment.

Why Others Are Wrong?

A: Declarative logic still requires maintenance (e.g., updates when fields change).
B: Declarative tools often have lower limits (e.g., Flow transaction limits).

Explanation:

The scenario describes a classic data integration and upsert operation. Here's a breakdown of why option C is the correct and most efficient technique:
The Core Challenge: The requirement is to take data from an external CSV file and update existing records in the Candidate_c object. The key identifier that links the rows in the CSV to the records in Salesforce is the primaryid_c field, which already contains unique values.
What is an External ID? An External ID is a custom field that has the "External ID" attribute set to true. This tells Salesforce that the field contains values from an external system (like the CSV file's ID numbers) that can be used to uniquely identify records during data operations, most importantly, during upserts.

How It Solves the Problem:
Once the primaryid_c field is marked as an External ID, Universal Containers can use standard Data Import tools (like Data Import Wizard or Data Loader) to perform an upsert operation.
During the upsert, they would map the "Primary ID" column from their CSV file to the primaryid_c External ID field in Salesforce.

The upsert operation will then:
Match: For each row in the CSV, Salesforce will check if a Candidate_c record already exists with that value in the primaryid_c field.
Update: If a match is found, the existing candidate record will be updated with the new data from the CSV row.
Insert: If no match is found (meaning it's a new candidate), a new Candidate_c record will be created.

This ensures all data rows are correctly mapped and processed in a single, streamlined operation.
Why It's the Best Choice: This approach requires no code (Apex). It leverages built-in, robust Salesforce data management features, making it the most efficient, maintainable, and scalable solution.

Why the Other Options Are Incorrect:

A. Create a Process Builder on the Candidate_c object to map the records.
Why it's wrong: Process Builder is an automation tool that reacts to record changes within Salesforce. It is not designed to handle the initial mapping and processing of bulk data from an external CSV file during an import. The data import would first need to find and update the correct records before Process Builder could even run.

B. Create a before Insert trigger to correctly map the records.
Why it's wrong: While an Apex trigger could be written to try and query for existing records based on the primaryid_c value, it is an overly complex and error-prone solution for this specific requirement.
➡️ It would be inefficient for large data volumes, as it could hit governor limits by performing a SOQL query for every new record in the import batch.
➡️ It is redundant because Salesforce already provides the upsert functionality natively through External IDs.
➡️ It would only work on insert, not update, unless specifically designed for both, which is what the built-in upsert already does perfectly.

D. Upload the CSV into a custom object related to Candidate_c.
Why it's wrong: This does not solve the core requirement of updating the Candidate_c records. It merely stores the new data in a separate holding object. This would then require additional and more complex automation (e.g., triggers, flows) to read from this new custom object, find the matching Candidate_c records, and update them. This introduces unnecessary complexity and a potential point of failure.

Reference:
Salesforce Help: Upsert Records - This document explains how to use the upsert operation and how it relies on an record ID or a designated External ID field to match records.

Explanation:

When Apex code makes an HTTP/REST callout, Salesforce does not allow the test method to make an actual external HTTP request. Instead, the developer must provide a mock response that simulates the external system.

For HTTP callouts, Salesforce provides the HttpCalloutMock interface. The test mock class should therefore implement HTTPCalloutMock.

Example:

@IsTest
global class MyHttpCalloutMock implements HttpCalloutMock {
    global HTTPResponse respond(HTTPRequest request) {
        HttpResponse response = new HttpResponse();
        response.setStatusCode(200);
        response.setBody('{"status":"success"}');
        return response;
    }
}

The test can then register the mock:

Test.setMock(HttpCalloutMock.class, new MyHttpCalloutMock());

Test.startTest();
    // Call the Apex method that performs the HTTP callout
Test.stopTest();

This allows the test to verify how the Apex code handles the simulated REST response without contacting the real external system.

Why the other options are incorrect

A. Implement WebServiceMock

Incorrect. WebServiceMock is used for testing Apex web service callouts, such as SOAP-based web services, rather than HTTP/REST callouts.

B. Extend WebServiceMock

Incorrect for two reasons. WebServiceMock is an interface, so it is implemented rather than extended, and it is not the appropriate mock for an HTTP REST callout.

C. Extend HTTPCalloutMock

Incorrect because HTTPCalloutMock is an interface. A class must use implements, not extends, to implement an interface.

D. Implement HTTPCalloutMock

Correct. HTTPCalloutMock is specifically designed to provide simulated responses for HTTP callouts in Apex tests.

Key exam point

Remember:

REST/HTTP callout → implements HttpCalloutMock
SOAP web service callout → implements WebServiceMock

Therefore, D is the correct answer.

Explanation:

Why Option C?

standardController: Specifies the primary object (Notice__c) for the Visualforce page.
extensions: Lists Apex controller extensions (comma-separated) to add custom logic.

Syntax Rules:

Object names use __c suffix (e.g., Notice__c).
Attributes are space-separated, not joined with underscores.

Why Not Other Options?

A: Incorrect syntax (page_controllers is invalid).
B: Uses page_controllers (invalid) instead of standardController.
D: Missing standardController and uses invalid extends attribute.

Explanations:

A. Bulk API & Storage Limits

True. Bulk API is optimized for large data volumes (up to 10k records/batch) but does not bypass storage limits.
Storage limits (e.g., data, file storage) are enforced in all environments, including sandboxes.

C. Sandbox Storage Limits

True. Salesforce sandboxes have tiered storage:

Developer Sandbox: 200 MB data + 200 MB file storage.
Developer Pro Sandbox: 1 GB data + 1 GB file storage.

Why the Others Are False:

B. Bulk API Bypassing Limits
False. No tool (Bulk API, Data Loader, etc.) can bypass Salesforce storage limits.

D. Data Import Wizard as a Client App
False. The Data Import Wizard is a built-in Salesforce UI tool (accessible via Setup), not a separate client application.