Which QoS preclassification option will require the use of the qos pre-classify command for the VPN traffic？ （）

A、A.VPN traffic needs to be classified based on the Layer2 header information

B、B.VPN traffic needs to be classified based on the IP precedence or DSCP

C、C.VPN traffic needs to be classified based on IP flow or Layer 3 information， such as source and destination IP address

D、D.VPN traffic with Authentication Header （AH） needs to preserve the ToS byte