Which three key metrics should you measure?

Your development team uses Scrum as its process framework. You need to identify key metrics for measuring
the effectiveness of any process changes.
Which three key metrics should you measure? (Each correct answer presents a complete solution. Choose three.)

A.
Number of story points delivered during the sprint

B.
Number of tasks added to the sprint after the sprint starts

C.
Number of bugs reported by testers

D.
Number of classes in the code-base

E.
Number of items added to the Product Backlog

F.
Number of manual test cases created