[单选题]
Suppose a skydiver jumps from a high-flying plane. What is fbul;fi8ivrr/kug.2 r 0z.7sher acceleu8p qz 8q8e1n43apfi d8ggbr:ration when she g:rp 8 8anb8gqz e4qu1dp83f ishe reaches terminal velocity?
A. It is essentially zero.
B. It is in the upward direction.
C. It is approximately $9.8 \; m/s^2$ downward.
D. It is a constant pointing upward.