Refer to the exhibit. Which statement about this command is true?
A. It must be configured on each PE router to enable the PE routers to receive multicast traffic for this particular MVRF.
B. It is used to set the designated router on a link using PIM-SM.
C. It must be configured on the PE and CE router to enable MP-BGP to send labels for CSC.
D. It is used to set the router that will server as the root bridge for STP.
