The product owner solicits the team to help groom the backlog every iteration because:

A. Value to the customer may vary based on timing such as windows of opportunity and variable market demand.

B. The risk assessment of outstanding stories may be different based on current knowledge, thus affecting the adjusted value and the backlog prioritization order.

C. The customer’s acceptance criteria of various stories may have changed, affecting the points estimated by the team.

D. The team may re-estimate the points associated with each story, affecting the next iteration backlog commitment.