A security engineer is troubleshooting a server in the DMZ, which cannot be reached from the Internet or the internal network. All other servers on the DMZ are able to communicate with this server. Which of the following is the MOST likely cause?

A.
The server is configured to reject ICMP packets.

B.
The server is on the external zone and it is configured for DNS only.

C.
The server is missing the default gateway.

D.
The server is on the internal zone and it is configured for DHCP only.