Joaquim wants to estimate the number of hairs on his head. He does some research and finds that, on average, people have about 300 hairs per cm2. He decides that half of a soccer ball is roughly equivalent to a person’s scalp area. If an official size 5 soccer ball has a radius of 11 cm, which is the most reasonable estimate for the number of hairs on his head? A. 3 × 107 hairs
B. 3 × 105 hairs
C. 3 × 104 hairs
D. 3 × 103 hairs
E. 3 × 106 hairs