What is the fundamental problem with multicasting on “hub and spoke” Frame Relay networks that PIM NBMA mode addresses?

A.
When a spoke router sends a Prune to the hub router, the hub router is unable to Prune the spoke

B.
When a spoke router sends a Prune to the hub router, the Prune message is dropped by the Frame Relay switch

C.
When a spoke router sends a Prune to the hub router, the other spokes receive the Prune instead of the hub router

D.
When a spoke router sends a Prune to the hub router, other spokes cannot override the Prune and get pruned themselves