According to Scrum principles, who decides how much work can be included in a Sprint?

The correct answer is that the Development Team decides how much work can be included in a Sprint. This is grounded in the Scrum framework, which emphasizes the self-organizing nature of Development Teams.

During Sprint Planning, the Development Team evaluates the work that needs to be done based on its capacity and the selected items from the product backlog, which are prioritized by the Product Owner. The Development Team has the expertise and understanding of their capabilities, past performance, and current commitments, allowing them to estimate how much work they can realistically complete within the Sprint.

The Scrum Master's role is to facilitate the process and help the team adhere to Scrum practices, but it is not their responsibility to determine the workload. The Product Owner is responsible for maximizing the value of the product and prioritizing work, but they do not dictate how much the Development Team should commit to in any given Sprint. Therefore, it is the Development Team that collectively decides the scope of work based on the technical and practical aspects of delivering the Sprint goal successfully.