How should a developer write the test to provide test coverage?

Posted by: Pdfprep Category: PDI Tags: , ,

A developer wrote Apex code that calls out to an external system.

How should a developer write the test to provide test coverage?
A . Write a class that extends HTTPCalloutMock.
B . Write a class that implements the HTTPCalloutMock interface.
C . Write a class that implements the WebserviceMock interface.
D . Write a class that extends WebserviceMock

Answer: B