The rectangular boat shown below has base dimensions 10.0 cm × 8.0 cm. Each cube has a mass of 40 g, and the liquid in the tank has a density of 1.0 g/mL. How far has the boat sunk into the water?
A. 3.2 cm
B. 4.0 cm
C. 4.8 cm
D. 8.0 cm