How can a Consultant ensure that Cases are closed when all Work Orders associated to the Case are complete?

Universal Containers (UC) wants to track the full lifecycle of their Cases. UC defines a Case as resolved when all interactions with the customer are complete.

How can a Consultant ensure that Cases are closed when all Work Orders associated to the Case are complete?
A . Use Workflow to close the Case when all Work Orders are closed.
B. Use Process Builder to close the Case when all Work Orders are closed.
C. Use Workflow to close the Case when the Work Order is dispatched.
D. Use Process Builder to close the Case when the Work Order is created.

Answer: B