Question: Typing `systemctl enable crond` does what to the crond service?

  1. Starts the crond service now.
  2. Allows user to start the crond service.
  3. Unmasks the crond service.
  4. Ensures that the crond service starts automatically on bootup.

Answer: The correct answer of the above question is Option D:Ensures that the crond service starts automatically on bootup.