Correct Answer: A
Antivirus softwareis apreventive security controldesigned to stop known malware threats before they can execute or spread within a system. Antivirus solutions use signature-based detection, heuristic analysis, and increasingly behavior-based techniques to block malicious code such as viruses, worms, trojans, and ransomware.
In contrast,IDS (Intrusion Detection Systems)andHIDS (Host-based IDS)are primarilydetective controls.
They monitor systems and networks for suspicious activity but do not inherently block threats.SIEMplatforms aggregate and analyze logs for visibility and correlation; they support detection and response but do not directly prevent threats.
According to NIST SP 800-53, preventive controls are designed to stop incidents from occurring, while detective controls identify events after or during occurrence. Therefore, antivirus is the correct choice as it directly prevents threats.