An administrator is establishing a new site-to-site VPN connection on a Cisco IOS router. The organization needs to ensure that the ISAKMP key on the hub is used only for terminating traffic from the IP address of 172.19.20.24. Which command on the hub will allow the administrator to accomplish this?
A. crypto isakmp identity address 172.19.20.24
B. crypto ca identity 172.19.20.24
C. crypto enrollment peer address 172.19.20.24
D. crypto isakmp key Cisco0123456789 172.19.20.24