Which of the following commands reboots the system when using SysV init? (Choose TWO correct answers.)

shutdown -r now sends a reboot signal immediately (time argument 'now' means no delay); the -r flag instructs the system to restart rather than halt after bringing services down cleanly.

shutdown requires a time argument before the optional message; 'shutdown -r "rebooting"' is invalid syntax because the quoted string is interpreted as the time parameter, which fails validation and does not execute a reboot.

In SysV init, runlevel 6 is defined as the reboot runlevel; telinit 6 instructs init to transition to that runlevel, causing the system to stop all services and restart.

telinit 0 transitions the system to runlevel 0, which is the halt runlevel that powers off or stops the system, not the reboot runlevel.

shutdown -k sends a wall warning message to logged-in users but explicitly does NOT perform any actual shutdown or reboot action; the -k flag stands for 'kick' and is used only for testing or warning purposes.