CompTIA Linux+ XK0-006 (V8) Practice Question

The correct command is passwd -l temp_user. The -l option locks the specified user's password by prepending an exclamation mark (!) to the encrypted password hash in the /etc/shadow file. This action prevents the user from authenticating with their password. The -u option is used to unlock an account that was previously locked with -l. The -d option deletes the user's password, which is a different action from locking it. The -e option expires the user's password, forcing them to change it at the next login, but it does not lock the account.