Answer: b. Push an unbent paper clip into the hole on the front of the drive.
Explanation:
Computer DVD drives come with a hole in front of them that is not too much larger than a pin's diameter. It is called an Emergency Eject Hole.
If you find that you need to retrieve a disk and the computer is off, find an unbent paper clip and push it into that hole. The DVD drive should open up thus enabling you to retrieve your disk.