Which of these statements is NOT correct about Ideal time and Calendar time?

A product owner feels that the last sprint failed to sufficiently deliver that was valuable to their organization's overall project goals.
What should the scrum master mention at the next retrospective?

During planning sessions, an agile practitioner notices that some team members do not share common ideas. What should the agile practitioner do?

At the end of first iteration, the team finishes User Stories A, Band 50% of
C. What is the team velocity?

The advantage of face-to-face collaboration emphasized in eXtreme Programming (XP) is that it: