Which Statement About Route Distinguishers in an MPLS Network Is

Which statement about route distinguishers in an MPLS network is true?

A) Route distinguishers allow multiple instances of a routing table to coexist within the edge router.
B) Route distinguishers are used for label bindings.
C) Route distinguishers make a unique VPNv4 address across the MPLS network.
D) Route distinguishers define which prefixes are imported and exported on the edge router.