What type of test is used to validate the system's compliance with non-functional requirements?

A performance test is specifically designed to evaluate how a system behaves under various conditions and ensures that it meets its non-functional requirements, such as responsiveness, scalability, and stability. Non-functional requirements are criteria that can be measured to determine the quality attributes of the system rather than specific functionalities. Performance testing assesses whether the system can handle expected loads, responds quickly enough to user interactions, and performs efficiently in terms of resource usage.

While unit tests focus on validating individual components or functions for correct computation, and security tests examine the system's defenses against various vulnerabilities, neither explicitly checks for overall system performance against non-functional benchmarks. User acceptance tests, on the other hand, are typically concerned with whether the system meets the business needs and requirements from an end-user perspective. Thus, performance tests distinctly address the validation of compliance with non-functional requirements, making it the most suitable choice.