You are designing a Group Encrypted Transport virtual private network solution for an existing branch network. The existing network has the following characteristics: - 50 remote sites (with an additional 30 remote sites expected over the next 3 years) - Connectivity between all sites is via Multiprotocol Label Switching Layer 3 virtual private network service from a single provider - Open Shortest Path First is the routing protocol used between provider edge and customer edge routers - The customer edge routers will become group members performing the encryption between sites Which additional routing protocol would you use for the overlay routing between the group members? 

Answer options:

A. Open Shortest Path First (with a different process ID)
B. Enhanced Interior Gateway Routing Protocol
C. No additional protocol is necessary.
D. External Border Gateway Protocol
E. Routing Information Protocol Version 2
F. Next Hop Resolution Protocol

C