When BGP is used as the PE-CE routing protocol, which of these statements is correct?（）

A.On the CE router, PE neighbors must be configured in the VRF context on the CE router

B.On PE routers, the CE IBGP neighbors are configured in the global BGP configuration

C.On PE routers, the CE EBGP neighbors are configured in the VRF context

D.A separate BGP process must be used on the PE routers for CE routers so that they do not use the same BGP routing process as that used for the PE router's other provider neighbors