What is true about OSPF running between PE and CE routers?

A.
Extra configuration is required to pass the OSPF route attributes from OSPF to MP-BGP.

B.
OSPF route attributes are carried as extended BGP attributes into MP-BGP.

C.
Extra configuration is required to pass the OSPF route attributes from MP-BGP to OSPF.

D.
Routes redistributed from MP-BGP to OSPF automatically maintain OSPF route attributes.