Laura was asked to estimate the volume of dirt in a large hill outside her school. She decides to model the hill using a truncated cone. She estimates that the hill has a base diameter of 80 feet, a top diameter of 40 feet, and a helght of 24 feet. What is the approximate volume of dirt in the hill?

A. 30,144 ft3
B. 70,336 ft3
C. 120,576 ft3
D. 281,344 ft3