In Multicast VPN （MVPN） implementations， which two of the following statements are regarding the DefaultMDT Group？（）
- AIt is used for PIM control traffic
- BIt is optionally configured for a high bandwidth multicast source to reduce multicast traffic replication to uninterested PE routers
- CWithin the VPF configuration in the PE router， multiple Default MDT groups are configured so each VPF can support multiple multicast sources
- DThere is a reduced multicast state in the MPLS core P routers
- EWhen multicast traffic exceeds a certain configured threshold， traffic from the Data MDT is switched to the Default MDT to conserve bandwidth