Refer to the exhibit.

When the link between RtrB and RtrC goes down, multicast receivers stop receiving traffic from the
source for multicast group 229.1.1.1.Which solution will resolve this?

A.
adding a static mroute on RtrB and RtrF

B.
adding a static unicast route on RtrB and RtrF

C.
creating a GRE tunnel between RtrB and RtrD

D.
enabling PIM sparse mode on both ends of the link between RtrB and RtrF