Which of the following would most likely prevent exploitation of an end-of-life, business-critical system?

Monitoring involves keeping an eye on system activity to detect potential security incidents. While it is essential for identifying threats, it does not actively prevent exploitation. An end-of-life system may still be vulnerable to attacks even if it is monitored, as the underlying security flaws remain unaddressed.

Decommissioning refers to the process of formally retiring a system. While this action effectively eliminates the risk of exploitation by removing the system entirely, it is not a preventive measure during the system's operational phase. Decommissioning is a final step, and until it occurs, the system may still be exposed to threats.

Encryption protects data by encoding it, making it unreadable without the appropriate keys. However, encryption does not address vulnerabilities in the system itself. An end-of-life system can still be exploited if it has unpatched security holes, regardless of whether the data is encrypted.