With Layer 3 MPLS VPN implementations on Cisco IOS XR PE routers, an interface is assigned to a VRF using the vrf command in which configuration mode?
A. RP/0/RP0/CPU0:PE(config-bgp)#
B. RP/0/RP0/CPU0:PE(config-if)#
C. RP/0/RP0/CPU0:PE(config-bgp-af)#
D. RP/0/RP0/CPU0:PE(config-vrf)#
