What best describes the quality characteristics or quality attributes in software development?

Quality characteristics or quality attributes in software development refer to the non-functional requirements that define how well a system performs its intended functions. These attributes encompass aspects like performance, scalability, security, usability, reliability, and maintainability.

When we say that option B represents the definition of how the system should behave, we are recognizing that quality attributes specify the expectations placed on the system's behavior under varying conditions. For example, a system may need to be responsive (performance), capable of handling increased load (scalability), or resistant to unauthorized access (security). These characteristics guide developers in ensuring that the system meets both the functional requirements and the necessary standards of quality.

In contrast, while the other options describe important aspects of software development, they do not encapsulate the essence of quality attributes. User interface design, documentation of system changes, and manuals for end-users are more focused on specific elements of the software and its operation rather than the overarching qualities that assess the software’s performance and user experience.