Which statement is true about the internal link between the Routing Engine and the Packet-Forwarding Engine？（）

• A、It is only used for exception traffic.
• B、It is an FE link called fxp2.
• C、It is rate-limited to avoid DDOS attacks.
• D、It is only used to send the forwarding-table from the Routing Engine to the Packet-Forwarding Engine.