Which of the following is the Development Team not responsible for?

The Development Team is not responsible for selecting the Product Owner. This responsibility typically lies with the organization or stakeholders who ensure that the right individual is appointed to represent the business and prioritize the work that the Development Team will accomplish. The role of the Product Owner is to manage the Product Backlog and act as a liaison between the stakeholders and the Development Team, which is distinct from the responsibilities of the Development Team itself.

In contrast, the Development Team has a direct role in deciding the Sprint length, as they recommend an appropriate duration based on their work dynamics and the rhythm they want to establish for delivering increments. They are also accountable for delivering a "done" increment at the end of each Sprint, which reflects their collaborative work in producing potentially releasable product functionality. Additionally, while the Development Team does not formally manage the Product Backlog—that is the responsibility of the Product Owner—they are involved in refining and providing input into it, allowing them to help shape the work they will commit to in Sprints.