Which TWO statements are correct about Product Backlog refinement?
a. Normally, it doesn't take more than 10% of the Product Owner's time.
b. Multiple teams may participate in it.
c. It can be done any time during the Sprint.
d. Normally, it shouldn't take more than 10% of the Scrum Team's time.
e. It should be timeboxed for 8 hours or less.
f. It should be done immediately before Sprint Planning.
