During iteration planning, it was determined that an epic should be decomposed. What was the determining factor?

Pick which 3 activities are the responsibilities of the Scrum Master in Scrum.

During a sprint review, the product owner identifies a required improvement for a feature's user interface (UI) delivered during the sprint.
What should the product owner do next?

An agile team has only one database administrator with the necessary knowledge of database-related tasks.
The project manager identifies the risk that if this person leaves, team velocity will significantly decrease.
What should the agile coach do?

Which of the following is an Agile Manifesto principle?