Which of the following about BGP Auto Discovery in an MVPN is TRUE? 

If BGP Auto Discovery is used, MPLS LSPs must be used for the P-tunnels in the MVPN. 

PIM state is maintained between PEs in the MVPN without PIM Hello messages. 

MP-BGP keepalive messages are used to maintain adjacencies between the PEs in an MVPN. 

MP-BGP can also be used as the multicast signaling protocol between the PEs and CEs.