You are creating your WBS and keep decomposing tasks into smaller units. How can you tell when you are done?

A.
Keep decomposing tasks until you reach an amount of work that is small enough to reliably estimate required resources and duration.

B.
Keep decomposing work until you reach a predetermined number of hierarchy levels to keep the WBS balanced.

C.
Keep decomposing tasks until you reach an amount of work that can be accomplished in one DAY.

D.
Keep decomposing tasks until you reach an amount of work that can be accomplished in one WEEK.

Explanation:
Keep decomposing tasks until you reach an amount of work that is small enough to reliably estimate required resources and duration.