How can blocker tickets best be used after they are solved?

A Scrum team has work-in-progress limits (WiP-limits) on their Kanban board. They also use blocker tickets to indicate a task that cannot move forward. Once the team has solved the blocker ticket they save it for later use.

How can blocker tickets best be used after they are solved?
A . Create affinity diagrams that show improvement themes and initiatives that the team should invest in
B. Discuss the blocker buckets during a sprint review meeting to find the root cause and the solution
C. Keep track of the number of blocker tickets to see if the team can get the number down over time
D. Record the blocker tickets in a continuous improvement backlog or the product backlog for later review

Answer: D