In order to configure two routers as anycast RPs， which of these requirements， at a minimum， must be satisfied？（）

A.Multicast Source Discovery Protocol mesh-groups must be configured between the two anycast RPs.
B.The RPs must be within the same IGP domain.
C.Multicast Source Discovery Protocol must be configured between the two anycast RPs.
D.The two anycast RPs must be IBGP peers.