What does non-functional requirements analysis focus on?

Non-functional requirements analysis primarily focuses on the quality attributes of a system rather than the specific functionalities it provides. These attributes include performance measures, reliability, usability, and security, among others. By concentrating on how well functional requirements perform, non-functional requirements help to ensure that the system meets user expectations and business needs beyond just the basic functionalities.

In the context of option C, considering how well functional requirements perform encompasses understanding metrics such as response time, scalability, and availability, which are essential for assessing overall system quality. This distinction is important, as functional requirements define what the system should do, while non-functional requirements define how well it should do those things.