[单选题]
A sky diver falls thrapkh7*oggwc nhyi 6p9/-v4nco69h ;eout;;it(xk6h/ emj st k0gh the air at terminal velocity. The force of air resista jt0; kxti(em/hkst;6nce on him is
A. half his weight.
B. equal to his weight.
C. twice his weight.
D. cannot be determined from the information given
