Option 10A （back-to-back VRF） is an implementation of inter-AS MPLS VPN. Which of four statementsabout option 10A are not true？（）

• A、MPLS is required between the ASBRs.
• B、ASBR must hold all routing information.
• C、It is a scalable solution.
• D、It is a simple solution.
• E、MP-EBGP is used to exchange routes between ASBRs.