Which statement about multicast VPN is true？（）

• A、The MDT group address should be the same for both address families in the same VRF
• B、The MDT group address should be the same for both address families in the different VRFs
• C、Configuration of the MDT source on a pre-VRF basis is supported only on IPv6
• D、The MDT group address should be different for both address families in the same VRF