Which protocol must you configure on R1’s ge-0/0/0 to forward multicast traffic toward the receiver?

D is the correct answer
The Multicast Listener Discovery (MLD) protocol manages the membership of hosts and routers in multicast groups. IP version 6 (IPv6) multicast routers use MLD to learn, for each of their attached physical networks, which groups have interested listeners. Each router maintains a list of host multicast addresses that have listeners for each subnetwork, as well as a timer for each address. However, the router does not need to know the address of the listeners—just the address of the hosts. The router provides addresses to the multicast routing protocol it uses; this ensures that multicast packets are delivered to all subnetworks where there are interested listeners. In this way, MLD is used as the transport for the Protocol Independent Multicast (PIM) protocol.

MLD is an integral part of IPv6 and must be enabled on all IPv6 routers and hosts that need to receive IP multicast traffic. Junos OS supports MLD versions 1 and 2. Version 2 is supported for the source-specific multicast (SSM) include and exclude modes.