Refer to the exhibit. The PE devices are Cisco ASR 9000 Series that provide L2VPN services according to the EVC model. The customer intends to run several C- tags on both ends of the connection. What happens to the existing VLANs on the Layer 2 transport on PEs that face the CEs? 

Answer options:

A. Existing VLANs are removed by default.
B. Existing VLANs need to be removed by using the rewrite command.
C. Existing VLANs are preserved by default.
D. Existing VLANs need to be reconfigured by using the encapsulation command.

C