[单选题]
Suppose that an 80-kg person wgznam2; vdz r+qeg( +;alking on crutches supports al. gts;uaj;7lt j;+ws rl his weight on the two crutch tis ;7jas;j;.t +wtuglr ps, each of which is circular with a diameter of 4.0 cm. What pressure is exerted on the floor?
A. $78 \; kPa$
B. $156 \; kPa$
C. $312 \; kPa$
D. $624 \; kPa$
