Ella is a Scrum Master. She used to attend or facilitate the different Scrum events: sprint, sprint planning, daily standup, sprint review, and sprint retrospective. Which of the following options describes the sprint retrospective meeting?

A meeting for defining and evaluating the work of the next sprint

A meeting for refining product backlog items

A meeting for discussing the negative and positive aspects of a sprint as well as any possible improvements

A meeting held at the end of the project's last sprint