In Linux, services that are set to restart automatically after a failure are said to be "Autorestart." This feature ensures that critical services can recover from failures and continue running, enhancing system reliability and availability.

In Linux, the visudo command is used to see who has been granted sudo access. This command opens the sudoers file in a safe manner for editing and displays the sudo configuration. It's important to use visudo to avoid syntax errors in the sudoers file, which could lock you out of administrative access.

systemd is the system in Linux that allows for the management and supervision of service daemons. It's a modern initialization system and service manager that replaces the traditional SysV init. systemd provides enhanced control and monitoring of services and system initialization.

The correct option is snapshot. Btrfs, a modern file system for Linux, provides a feature that allows for creating a readable/writable "snapshot" of a subvolume. Snapshots are a powerful tool for data protection and efficient use of disk space.