What type of testing assesses how well a program meets the specified requirements?

Functionality testing is focused on evaluating how well a software program meets the specified requirements and expected behaviors. It involves checking the application’s features to ensure they work as intended and fulfill the criteria outlined during the requirements phase of the project development life cycle. This type of testing ensures that all functionalities perform correctly in accordance with the requirement specifications.

Performance testing generally assesses the speed, responsiveness, and stability of a program under a particular workload but does not necessarily judge whether the requirements are being met. Usability testing focuses on how easy and intuitive a program is to use from the end user's perspective and also does not directly assess the correctness of the features against requirements. Unit testing is more about validating individual components of code for correctness rather than the software as a whole meeting specified requirements. Therefore, functionality testing is the most appropriate choice for determining if all specified requirements are satisfactorily implemented in the software.