A. to enable label switching on the frame mode interface
B. to restrict MPLS availability to predefined time periods
C. to restrict end users from seeing the routers in the MPLS network
D. to restrict label switching to a limited number of networks

A. If using OSPF or EIGRP as the PE-CE routing protocol, redistribution is not required, but any other protocol or static route will require redistribution
B. If using IS-IS as the PE-CE routing protocol, no redistribution is required
C. If using static routes between the CE and PE routers, no redistribution of other VPN routes is required
D. If PE-CE protocol is not BGP, redistribution of other VPN routes from MP-BGP is required