A. The supervisor module enforces CoPP before out-of-policy traffic reaches the CPU
B. The fabric modules enforce CoPP in the fabric before out-of-policy traffic reaches the CPU 
C. The linecards enforce CoPP locally before out-of-policy traffic reaches the CPU
D. The egress virtual output queue enforces CoPP locally before out-of-policy traffic reaches the CPU

A. on all ingress interfaces； to ensure maximum throughput on a per-egress， per-CoS basis
B. on all ingress interfaces； to provide independent congestion management and 16 queues
C. on all egress interfaces； so that a congested egress port does not affect traffic directed to other egress ports
D. on all egress interfaces； to prevent head-of-line blocking by utilizing multiple virtual output queues
E. on all egress interfaces； to be able to use EEE 802.1p CoS