A. CEF switching is not needed for MPLS operation.
B. CEF switching is only needed to forward labeled packets.
C. CEF switching is needed on both ingress and egress interfaces on which MPLS is enabled.
D. Interface-level CEF switching is needed only on egress interfaces that are sending IP packets on which the egress LSR performs the label imposition process.
E. Interface-level CEF switching is needed only on ingress interfaces that are receiving IP packets on which the ingress LSR performs the label imposition process.