The length of a Sprint should be:

Which phrase best describes a Product Owner?

The time-box for a Daily Scrum?

Marian is the Product Owner envisioning a project for a new release of her product. She made a projection of a release date based upon a sustained velocity of 17 completed units of work per Sprint. Over the first 3 Sprints, the average velocity was 13 for work that the Development Team estimated as 90% done. The Development Teams, feeling the need to meet the plan, figured that a velocity of 17 was within their reach. A good way to continue is:

The Product Owner is not collaborating with the Development Team during the Sprint. What are two valuable actions for a Scrum Master to take?