ISV Package Development:
The ISV is developing a managed package.
They have an Apex class BodyFat with a method calculateBodyFat().
Requirement:
Ensure calculateBodyFat() is accessible by consumers outside the package namespace.
Solution:
To allow methods in a managed package to be accessible outside the package namespace, they must be declared as global.
Option B: Declare the class and method using the global access modifier.
Correct Approach.
Global Classes and Methods:
In managed packages, only classes and methods declared as global are accessible outside the package namespace.
Declaration:
global class BodyFat {
global void calculateBodyFat() {
// method implementation
}
}
Important Notes:
Public classes and methods in managed packages are accessible only within the namespace.
Global is required to expose the functionality to subscribers.
The method must also be declared as global to be accessible outside the namespace.
Using public on the method limits its accessibility to within the namespace.
Option C: Declare the class and method using the public access modifier.
Incorrect.
Public classes and methods in a managed package are only accessible within the package's namespace.
They are not accessible to subscribers.
Option D: Declare the class as public and use the global access modifier on the method.
Incorrect.
The class must be declared as global to be accessible outside the namespace.
A public class cannot contain global methods.
Conclusion:
To ensure calculateBodyFat() is accessible outside the package namespace, both the class and method must be declared as global.
Therefore, Option B is the correct choice.
Reference:
Apex Class Access Modifiers
Developing Packages with Apex
Why Other Options are Not Suitable:
Option A: Declare the class as global and use the public access modifier on the method.
Incorrect.

When writing tests for Apex code that performs callouts to external services, Salesforce requires that callouts are mocked to ensure that tests do not depend on external systems and to allow for consistent and predictable test results.
Correct Option:
Option D: Write a class that implements HttpCalloutMock.
True.
To test HTTP callouts, you implement the HttpCalloutMock interface and provide a fake response for the HTTP request.
This mock response is then used in your test methods to simulate the callout.
The test method uses Test.setMock to set the mock class.
WebServiceMock is used for testing SOAP callouts, not REST (HTTP) callouts.
Since the code uses REST API, HttpCalloutMock is appropriate.
HttpCalloutMock is an interface, not a class. You cannot extend an interface; you implement it.
The correct approach is to implement the HttpCalloutMock interface.
Reference:
Testing HTTP Callouts by Implementing HttpCalloutMock
Incorrect Options:
Option A & C: Write a class that implements or extends WebServiceMock.
False.
Testing SOAP Callouts
Option B: Write a class that extends HttpCalloutMock.
False.
Interface vs. Class
Conclusion:
To properly test REST API callouts in Apex, you should write a class that implements HttpCalloutMock and use it in your test methods.