When EIGRP is used as the PE-CE routing protocol which of these statements is correct?（）
- A EIGRP can be used only as the PE-CE routing protocol if the PE and CE routers are in the same AS
- B Other EIGRP AS routes are automatically advertised to the CE router and do not require a redistribution configuration command to be configured
- C Unlike other routing protocols that are used between PE and CE routers, EIGRP supports backdoor links
- D Configure of the VPN is only required on the PE router