You need a tool that can do network intrusion prevention and intrusion detection, function as a network sniffer, and record network activity. What tool would you most likely select?

Snort is a widely used open-source network intrusion detection and prevention system that also operates as a packet sniffer and network activity logger. It supports three primary modes - sniffer mode, packet logger mode, and full NIDS/NIPS mode. No other option in the list provides all four capabilities simultaneously.

Nmap is a port scanner and host discovery tool, not an IDS/IPS or network sniffer with logging capabilities.

Cain and Abel is a Windows-based password recovery and credential-cracking tool, not an intrusion detection or sniffing platform.

Nessus is a vulnerability assessment scanner that identifies security weaknesses but does not perform intrusion prevention or packet sniffing.