A body of water with a depth of 10 m creates a pressure equal to atmospheric pressure. A bubble of air moves upward to the surface of a lake that is 20 m deep. When the bubble arrives at the surface, its volume is 6.0 cm$^3$. What is the volume of the air bubble at the bottom of the lake?
- A2.0 cm$^3$
- B3.0 cm$^3$
- C12 cm$^3$
- D18 cm$^3$