Which two statements are accurate about why Mock objects are needed when writing test classes?

The correct selection is A, D. HTTP callouts in Apex tests require mocks, and mocks more broadly isolate a unit from dependencies whose state or behavior must be controlled. They make tests deterministic and let developers simulate success and failure conditions without contacting external systems or bypassing normal Batch Apex testing patterns. From a testing perspective, the goal is deterministic evidence that the solution behaves correctly under the conditions that matter. Tests should isolate external dependencies, use controlled data, exercise positive and negative paths, and reproduce realistic volume or user behavior where required without making production the first place defects are discovered. The alternatives do not provide equivalent evidence: they either validate only a narrow implementation detail or depend on conditions outside the test ' s control. For this scenario, the decisive point is therefore the platform behavior represented by the selected options (A. Mock is needed whenever the code makes an HTTP callout.; D. Using a Mock allows the test class to bypass the dependencies of other objects, methods, state, or behaviors. Therefore, the developer has total control of his own code.). Applying that rule consistently keeps the implementation aligned with Salesforce-supported lifecycle practices and makes the resulting change easier to review, validate, and operate across environments.

Study Guide reference: Testing — Apex testing; test-data isolation; mocks; regression testing; performance/load testing; sandbox test strategy.