The ability of a robust HIPS to perform analysis of system calls, application state, and overall system behavior to prevent malicious activity distinguishes it from signature-based detection methods. This functionality allows it to identify and block potentially malicious actions, such as those associated with zero-day attacks, by looking at abnormal activities that do not match the typical behavior of the system, rather than relying on a database of known threats. The incorrect answers either describe functions of other security tools or are more reactive measures, rather than the proactive behavioral monitoring performed by HIPS. Antivirus primarily relies on signature matching; system hardening includes measures like closing unused ports and disabling unnecessary services, and log analysis, while critical for identifying past incidents, is not a prevention method.