3. A submarine fills a special storage area known as a ballast with water in order to
increase its density. This allows it to dive deeper in the ocean. When a submarine
needs to rise rapidly, compressed air is used to push the water out of the ballast.
What effect does replacing the water in the ballast with air have on the submarine?
A. The submarine's volume increases, lowering its density.
B. The submarine's mass decreases, lowering its density.
C. The submarine's mass increases, raising its density.
D. The submarine's volume decreases, decreasing its density.