You are auditing the network design of a PIM BiDir multicast network. Which option is the most appropriate multicast group source discovery design consideration for this design?
A. A phantom RP advertises the multicast group sources.
B. Source discovery is not applicable to PIM BiDir.
C. Subscribers discover the multicast group sources via DNS.
D. Subscribers are statically configured with specific sources.
E. MSDP is used to discover multicast group sources.
