[单选题]
A sky diver falls through the air at termi6; h mesldnki.t/0 az,nal ifpu 3qfbi*-*n(ki f- velocity. The force of air resistfuki*iffqb(-3n ip-* ance on him is
A. half his weight.
B. equal to his weight.
C. twice his weight.
D. cannot be determined from the information given
