Which of the following are init systems used within Linux systems? (Choose THREE correct answers.)

startd is not a recognized or standard init system used in Linux environments.

systemd is the modern and widely adopted init system in most contemporary Linux distributions, managing system services, targets, and the overall boot process.

Upstart was an event-driven init system developed by Canonical and used in various Linux distributions, most notably Ubuntu, prior to the widespread adoption of systemd.

SysInit is not a recognized or standard init system used in Linux environments; it appears to be a generic or made-up term.

SysV init (System V init) is the traditional and older init system historically used in many Unix-like operating systems, including early Linux distributions, managing services through run levels.