What defines a 'use case' in Agile software development?

A 'use case' in Agile software development defines a requirement for user interactions by describing how a user will interact with the system to achieve a specific goal. It focuses on the end user experience and outlines the actions that users take and the system's responses, providing a practical perspective on user requirements. This aligns with Agile principles, which prioritize customer collaboration and responsiveness to change.

Use cases typically include various scenarios involving the user, detailing both the main flow and alternative flows of interaction. This helps in clarifying what functionalities are needed from the user's viewpoint and supports the development team in understanding the requirements better.

In contrast, other options do not accurately capture the essence of what a use case represents in Agile. Option A relates more to verification processes rather than user-focused interactions. Option C focuses on internal structures, which are not the primary concern of use cases. Option D may suggest documentation but doesn't emphasize that use cases specifically address user interactions, making B the most appropriate definition.