Diagram 1 illustrates a measuring cylinder that contains water. A metal weight, with a cork fastened to it by a thread, is suspended above the water. Diagram 2 illustrates the apparatus once the weight has been lowered into the water. Diagram 3 illustrates the apparatus after both the weight and the cork have been submerged. Find the volume of the cork.
- A$20\ \text{cm}^3$
- B$30\ \text{cm}^3$
- C$45\ \text{cm}^3$
- D$70\ \text{cm}^3$