What function does MP-BGP provides that is required for MPLS layer 3 VPM services?

What function does MP-BGP provides that is required for MPLS layer 3 VPM services?

A.
MP-BGP modifies or swaps the LDP label to indicate the next-hop router in MPLS cloud

B.
MP-BGP provides the penultimate hop popping function

C.
MP-BGP performs the standard MPLS LDP functions in layer 3 environment

D.
MP-BGP advertises the VPN label and identifies the correct egress PE interface