What show command can see vpn tunnel establish with traffic passing through?

A.
show crypto ipsec sa

B.
show crypto session

C.
show crypto isakmp sa

D.
show crypto ipsec transform-set

Explanation:
#show crypto ipsec sa – This command shows IPsec SAs built between peers In the output
you see
#pkts encaps: 345, #pkts encrypt: 345, #pkts digest 0
#pkts decaps: 366, #pkts decrypt: 366, #pkts verify 0
which means packets are encrypted and decrypted by the IPsec peer.
http://www.cisco.com/c/en/us/support/docs/security-vpn/ipsec-negotiation-ike-protocols/5409-
ipsec-debug-00.html#ipsec_sa