A. systemd reads /etc/system to determine which services to start.

B. The service command is used to start and stop system service units.

C. systemd is backward-compatible with the System V init scripts that were used in earlier versions of Oracle Linux.

D. systemd service units expose kernel devices and can be used to implement device-based activation.

E. systemd is the first process that starts after the system boots and is the final process left running before the system shuts down.