Click the Exhibit button.

RP1 and RP2 are acting as PIM-SM rendezvous points (Rps) in their autonomous system.
Referring to the diagram, which purpose does the MSDP session between RP1 and RP2 serve?

A.
MSDP allows RPs in different PIM domains to advertise any active multicast receivers to each other.

B.
MSDP allows RPs in different PIM domains to advertise any active multicast sources to each other.

C.
MSDP routes are used by an RP for reverse path forwarding lookups when milticast sources exist in
different autonomous systems.

D.
MSDP allows RPs in different PIM domains to form PIM neighbor relationship with each other.

Explanation:
The Multicast Source Discovery Protocol (MSDP) is used to connect multicast routing domains. It typically runs
on the same router as the Protocol Independent Multicast (PIM) sparse-mode rendezvous point (RP). Each
MSDP router establishes adjacencies with internal and external MSDP peers similar to the way BGP
establishes peers. These peer routers inform each other about active sources within the domain. When they
detect active sources, the routers can send PIM sparse-mode explicit join messages to the active source.
http://www.juniper.net/techpubs/en_US/junos15.1/topics/concept/multicast-msdp-overview.html