An application's performance is degrading over time.

Comprehensive and Detailed Explanation From Exact Extract:

Resource Monitor provides real-time monitoring of system performance and resource usage, including CPU, memory, disk, and network usage. It helps technicians identify performance bottlenecks (e.g., high memory or CPU usage) that can cause slowdowns in applications over time without producing crash errors.

A. Reliability history logs application crashes or errors — not helpful if the app doesn’t crash.

B. Computer Management is a broad utility with limited real-time monitoring capability.

D. Disk is too vague — tools like CHKDSK can help with disk errors but not general performance degradation.