What type of requirement is related to how a system should perform?

The correct answer focuses on non-functional requirements, which describe how a system should perform rather than what it should do. These requirements encompass various quality attributes such as performance, usability, reliability, and security. They set the criteria for the operation of a system and help ensure that user needs surrounding these qualities are met.

For example, a non-functional requirement might specify that a system must be able to handle 1000 users simultaneously or that the response time for any transaction must be under two seconds. These aspects are crucial for user satisfaction and overall system performance but do not define any specific functionality or features of the system itself.

In contrast, functional requirements detail the specific behaviors or functions of a system, technical requirements often concern the technical constraints under which the system must operate, and business requirements typically relate to the needs and objectives of the organization rather than specific system performance metrics.