What is the correct Cisco IOS XR command to configure an autonomous system number 1000 for BGP and to support IPv4, IPv6, and unicast routing?
A. router bgp 1000address-family
ipv4 unicast
! address-family ipv6 unicast
!
!
B. router bgp 1000neighbor
1.1.1.1 remote-as 2000
address-family ipv4 unicast
!
address-family ipv6 unicast
!
!
C. router bgp 1000address-family
vpnv4 unicast
!
address-family vpnv6 unicast
!
!
D. router bgp 1000neighbor
1.1.1.1 remote-as 2000
address-family vpnv4 unicast
!
address-family vpnv6 unicast
!
!
