A web server was compromised through DNS hijacking.

DNS hijacking occurs when attackers manipulate DNS responses to redirect traffic to malicious servers. CEH v13 clearly identifies DNSSEC (Domain Name System Security Extensions) as the primary defense against such attacks.

DNSSEC adds cryptographic signatures to DNS records, enabling clients to verify authenticity and integrity of DNS responses. Without DNSSEC, attackers can spoof DNS responses even if servers are fully patched.

Changing IP addresses and using LAMP do not address DNS trust. Patching is essential but does not prevent DNS spoofing.

CEH v13 explicitly recommends DNSSEC for preventing cache poisoning and DNS hijacking attacks, making Option C the correct answer.