TestOut Linux Pro Practice Test 2025 – Complete Exam Prep Guide

Using the shutdown command with the appropriate syntax allows you to schedule a system shutdown effectively. The choice that includes `shutdown -h +15 "It is time for a shutdown!"` is correct because it instructs the system to halt (indicated by the `-h` option) after a 15-minute delay, as designated by `+15`. Additionally, the message provided in quotes ensures that users logged into the system receive a specific notification regarding the impending shutdown.

This command is particularly useful for system administrators who need to perform a controlled shutdown while informing users of the reason behind it. The inclusion of a delay over a direct immediate shutdown helps to prevent data loss by allowing users to save their work and log off gracefully before the system goes down.

In contrast, other options either do not incorporate the necessary time specification or misplace the message functionality. For instance, using `shutdown now` does not allow for a delay, and including a message in that command would not be syntactically correct. Similarly, `shutdown +15` lacks the `-h` flag, which means the system would initiate a reboot instead of halting, and fails to convey the message to the users.