A DNS server responds with different IP addresses rapidly for the same domain, pointing to...

The correct answer is C, Fast flux. Fast flux is a DNS-based evasion technique commonly associated with botnets, malware hosting, phishing infrastructure, and command-and-control resilience. In fast flux, one domain name is mapped to many rapidly changing IP addresses, often with very short DNS TTL values. This causes clients resolving the same domain to receive different destination hosts over time, making takedown, blocking, and attribution harder. CEH DNS fundamentals explain that DNS translates human-readable names into IP addresses and that DNS responses may contain address mappings that are cached according to Time-to-Live values. The described behavior—rapidly rotating IP addresses for the same domain—matches fast flux, not DNS tunneling, which hides data inside DNS queries; not DNS poisoning, which inserts false DNS records; and not zone transfer, which copies DNS zone records between servers. Therefore, the technique being used is fast flux.