John works as a Network Security Professional. He is assigned a project to test the security of Intrusion Detection System on the We-are-secure server so that he can receive alerts about any hacking…

SARA (Security Auditor's Research Assistant) is a network vulnerability scanning tool used to identify weaknesses in systems, not an IDS that generates real-time alerts about active hacking attempts.

Snort is an open-source network-based intrusion detection and prevention system (NIDS/NIPS) that performs real-time traffic analysis and packet logging, generating alerts when traffic matches known attack signatures - making it directly suitable for monitoring a server for hacking attempts.

Tripwire is primarily a file integrity monitoring tool that detects unauthorized changes to files after the fact, and is not designed as a full-featured IDS for generating real-time hacking attempt alerts.

Samhain is a host-based intrusion detection system (HIDS) that monitors file integrity, detects rootkits, and generates security alerts for unauthorized changes or suspicious activity on a host, fulfilling the requirement to receive alerts about hacking attempts.