Which of the following is considered a proactive security measure?

The correct choice recognizes vulnerability scanning and remediation as a proactive security measure. This process involves actively searching for potential vulnerabilities in systems before they can be exploited by attackers. By identifying and addressing these weaknesses, organizations can significantly reduce their risk exposure. This proactive approach ensures that security gaps are closed, updates are applied, and proper configurations are enforced, which helps maintain a stronger security posture.

In contrast, incident response planning is more about preparing for security incidents after they occur, making it a reactive measure. Running antivirus scans typically aims to detect existing threats rather than prevent them, placing it in a more reactive context, although it can have some proactive elements. Monitoring user activity is generally about observing what users are doing in real time, which is also a reactive measure since it's often used to detect and respond to suspicious activities after they happen.