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.