What is the proper MP-BGP configuration between the shown PE routers to implement MPLS VPNs on PE-R2 ? (Exhibit)

A.
router bgp 1
neighbor 50.0.0.4 remote-as 1
neighbor 50.0.0.4 update-source Loopback0
no auto-summary
!
address-family ipv4
neighbor 50.0.0.4 activate
neighbor 50.0.0.4 send-community extended
exit-address-family

B.
router bgp 1
neighbor 50.0.0.4 remote-as 1
neighbor 50.0.0.4 update-source Loopback0
no auto-summary
!
address-family vpnv4
neighbor 50.0.0.4 activate
neighbor 50.0.0.4 send-community extended
exit-address-family

C.
router bgp 1
neighbor 50.0.0.4 remote-as 1
neighbor 50.0.0.4 update-source Loopback0
no auto-summary
!
address-family vpnv4 unicast multicast
neighbor 50.0.0.4 activate
neighbor 50.0.0.4 send-community extended
exit-address-family

D.
None of the above