Which of the following best describes Non-functional User Stories?

Non-functional User Stories are best described by their focus on aspects of a system's performance and quality that do not directly relate to specific functionality. They concentrate on attributes such as reliability, scalability, performance, and security, which enhance the overall user experience and system efficiency but are not tied to a specific feature that a user directly interacts with.

Option B highlights that these stories provide benefits indirectly, such as performance enhancements. For example, while a functional user story might ask for a new feature like a search function, a non-functional user story could focus on the system's responsiveness and how quickly search results should be returned. This is crucial for maintaining user satisfaction but doesn’t introduce new features.

In contrast, the other options do not accurately capture the essence of non-functional user stories. For instance, while functional user stories often relate to features that users can directly interact with, non-functional stories do not add new features but instead focus on improving the system's performance or quality standards. Similarly, non-functional stories do not solely concentrate on user experience updates, as their scope is broader, encompassing various system qualities. Lastly, while these stories can be informed by user perspectives, they are not limited to being voiced solely from that viewpoint; they may also consider technical perspectives and business