Why is the definition of "Done" important for the Product Owner?

The definition of "Done" is crucial for the Product Owner as it provides assurance that the Increment produced by the Scrum Team is truly usable and meets agreed-upon criteria. This clarity is essential for assessing the quality and completeness of work, allowing the Product Owner to make informed decisions about the Increment's potential release to stakeholders or end-users.

By having a well-defined "Done," the Product Owner also gains transparency regarding the team's progress. It establishes a shared understanding among team members, stakeholders, and the Product Owner about what it means for work to be complete. This transparency is vital for managing stakeholder expectations and ensuring that the Increment delivers real value.

In contrast to this, other options do not capture the essential role of the definition of "Done." For instance, adhering to a strict timeline is more about project management and scheduling rather than the actual deliverable's quality. Increasing the size of the team or having a requirement for all Scrum teams is less related to the specific responsibilities of the Product Owner and does not address the critical aspect of ensuring that the Increment is usable or that progress is transparent.