Which command runs poweroff. target to shutdown the system?

This is one of the most useful systemD commands : systemctl isolate poweroff.target. For example, if you have a problem with a server and you want to bring the system down so that you could then reseat the card before restarting it, you can use this command, it will shut down the system in an orderly manner.

The correct answer would be a.

You need to call the office. and then you need to give them a reason on why you want to change your username.