What type of testing verifies the system's functional requirements based on…

Black-box testing is the correct answer because it validates system functionality from an end-user perspective without requiring knowledge of internal code structure. This approach directly aligns with user stories, which describe what the system should do rather than how it is implemented. Testers focus on inputs and expected outputs to verify that functional requirements are met, making it ideal for acceptance testing based on user stories. In contrast, white-box testing examines internal logic and code paths, which is unnecessary for validating user-facing requirements. Similarly, unit testing focuses on individual components rather than overall system behavior defined by user stories. Integration testing checks interactions between modules but does not primarily verify functional requirements against user narratives in the same direct manner as black-box testing.