Which of the following regular maintenance tasks for a workgroup of Windows PCs is MOST likely to be performed on a nightly basis?

CHKDSK scans and repairs the file system and is typically run only when disk errors are suspected, not on a nightly schedule, because it requires exclusive disk access.

Patch installation is usually performed on a weekly or monthly cycle, often following vendor release schedules like Microsoft's Patch Tuesday, not nightly.

Defragmentation is typically scheduled weekly or monthly for HDDs because running it too frequently wastes resources and is unnecessary for SSDs.

Nightly backups ensure that at most one day of work is lost in the event of a hardware failure, ransomware attack, or accidental deletion. Running backups after business hours minimizes impact on system performance and network bandwidth. This is a widely accepted best practice in IT operations for workgroups and enterprises alike.