In a PIM Sparse Mode Network, How to Restore the Flow

In a PIM sparse mode network, how to restore the flow of multicast traffic when a link fails along a branch of a multicast distribution tree?

A) The traffic reverts to the shared tree while the downstream router recalculates the RPF interface and sends a new PIM join message to the RP.
B) The downstream receivers notice the loss of the multicast flow and resend PIM join messages to reestablish the tree.
C) The downstream receivers notice the loss of the multicast flow and resend IGMP Membership Reports to reestablish the tree.
D) The router downstream of the break recalculates the RPF interface when it notices a change in the unicast routing table and immediately sends a new PIM join message out from the new RPF.