Which three MPLS statements are true？（）

• A、Cisco Express Forwarding （CEF） must be enabled as a prerequisite to running MPLS on a Cisco router.
• B、Frame-mode MPLS inserts a 32-bit label between the Layer 3 and Layer 4 headers.
• C、MPLS is designed for use with frame-based Layer 2 encapsulation protocols such as Frame Relay， but is not supported by ATM because of ATM fixed-length cells.
• D、OSPF， EIGRP， IS-IS， RIP， and BGP can be used in the control plane.
• E、The control plane is responsible for forwarding packets.
• F、The two major components of MPLS include the control plane and the data plane.