Apple Certified Support Professional (ACSP) Practice Exam 2025 - Free ACSP Practice Questions and Study Guide

When the backup disk is unavailable, Time Machine takes local snapshots as a way to ensure that data is still being backed up even when the designated external backup drive is not accessible. These local snapshots are stored on the internal hard drive, allowing users to recover files or previous versions of files even if the external backup disk is not connected. This feature is particularly useful for users who may not have their external drive attached all the time, as it provides a form of continuous data protection.

The other options do not accurately describe the behavior of Time Machine when faced with an unavailable backup disk. While Time Machine does not stop all processes entirely nor automatically delete old backups in this situation, it instead creates these local snapshots as a proactive measure to safeguard user data. Sending an error message to the user might occur in some instances, but the main functionality in response to an unavailable backup disk is the creation of local snapshots.