An architect is designing a multicast solution for a network that contains over 100 routers. The architect plans to create several multicast domains and balance the PIM-SM traffic within the…

DVMRP (Distance Vector Multicast Routing Protocol) is an older, dense-mode multicast routing protocol that is rarely used in modern networks and does not provide inter-domain source discovery for PIM-SM.

IGMP (Internet Group Management Protocol) is used by hosts to signal multicast group membership to their local routers, not for inter-domain routing or balancing PIM-SM traffic.

MOSPF (Multicast OSPF) is an extension of OSPF for multicast routing, but it operates within a single OSPF domain and does not provide the inter-domain source discovery needed for multiple PIM-SM domains.

MSDP (Multicast Source Discovery Protocol) is used to connect multiple PIM-SM domains and allow sources in one domain to be discovered by RPs (Rendezvous Points) in other domains, enabling inter-domain multicast routing and facilitating load balancing across different PIM-SM instances.