Final answer:
Priority is the most important attribute of a requirement as it determines the level of importance and helps stakeholders prioritize.
Step-by-step explanation:
The most important attribute of a requirement is its Priority. Priority determines the level of importance of a requirement and helps stakeholders prioritize their efforts and allocate resources accordingly.
For example, in a software development project, if the priority of a requirement is 'High', it means that it should be implemented early in the development process and given more attention compared to requirements with lower priority.
Priority allows stakeholders to make informed decisions about resource allocation and ensures that the most critical requirements are addressed first.