n this scenario, the technician should use Disk Cleanup. Disk Cleanup is a utility in Windows that helps free up disk space on a computer's hard drive by deleting temporary files, system files, and other unnecessary files that accumulate over time. This can help improve the performance of the system by clearing out clutter and freeing up space for the operating system and applications to work more efficiently. While Disk Defragmentation can also help improve performance on HDDs by reorganizing fragmented data on the disk, it might not be as effective in this case because the issue seems to be more related to the accumulation of large files rather than fragmentation. Disk Cleanup would be the more appropriate tool for addressing this specific issue.

A. Use disk defrag to optimize the used hard drive sectors, leading to improved performance.