Which access list entry checks for an ACK within a packet header?

ccnp-dump
ccnp-route-dump
ccnp-route

#1

Which access list entry checks for an ACK within a packet header?
A. access-list 49 permit ip any any eq 21 tcp-ack
B. access-list 49 permit tcp any any eq 21 tcp-ack
C. access-list 149 permit tcp any any eq 21 established
D. access-list 49 permit tcp any any eq 21 established

Correct Answer: C