Which option describes the incorrect usage of the Label Distribution method?

Which option describes the incorrect usage of the Label Distribution method?

A.
MP-BGP is used for label distribution for VPN customer routes.

B.
LDP is primarily used in internal networks of MPLS-VPN providers.

C.
MP-BGP is used for label distribution in MPLS Traffic Engineered networks.

D.
Directed LDP is used for label distribution in L2-VPN Attachement Circuits.