What does system testing primarily evaluate?

System testing primarily evaluates the functioning of the system as a whole, ensuring that all discrete modules or components interact correctly and meet the specified requirements. This phase of testing encompasses the entire integrated system environment, focusing on validating that all parts operate together seamlessly.

This evaluation process is crucial in identifying issues that may not arise when testing individual components alone, as interactions among modules can sometimes lead to unexpected behavior. The goal of system testing is to verify that the system performs as intended in its intended environment, validating both functional and non-functional characteristics such as performance, usability, and security.

While the other choices touch on aspects of testing, they do not encapsulate the primary purpose of system testing. Preparing for tests, testing individual programs, or providing final certification represent different phases or types of testing that support the overall testing lifecycle but do not specifically highlight the holistic evaluation provided by system testing.