During which Scrum event can adjustment of the definition of "Done" occur?

The adjustment of the definition of "Done" occurs during the Sprint Retrospective. This event provides an opportunity for the Scrum Team to reflect on their processes, practices, and outcomes from the previous Sprint. Since the definition of "Done" is a key component that helps ensure the quality and completeness of the increment, it is appropriate for the team to review and refine it during this reflective session.

During the Sprint Retrospective, the team discusses what went well, what didn’t, and how they can improve. If they recognize that the current definition does not adequately reflect the standards they're aiming for or if the team’s understanding has evolved, they can make informed adjustments to that definition. This continuous improvement aspect is crucial for promoting high-quality outputs and keeping the team aligned with their goals.

The other options relate to different processes in Scrum. The Sprint Review focuses on inspecting the product increment and adapting the Product Backlog, while Sprint Planning is oriented towards determining what can be done in the upcoming Sprint. The Daily Scrum is a brief meeting for synchronization among team members and is not focused on overarching definitions or policies. Therefore, it is during the Sprint Retrospective that the team has the right context to reconsider and enhance their definition of "Done."