In relation to MPLS Multicast VPN, which three statements about multicast distribution (MDT) groups aretrue? ()
A. Default MDT groups are used for PIM control traffic, low-bandwidth sources, and flooding of sparse mode traffic.
B. MDTs are built in customer networks
C. Data MDT groups are used for high-bandwidth sources to reduce replication to uninterested PEs.
D. MDTs are built in provider networks
E. The number of MDTs depends on PIM modes of MDT groups.