A parachutist jumps out of a plane. He falls freely for some time, and then opens his chute. Shortly after his chute inflates the parachutist(A) keeps falling but quickly slows down.(B) momentarily stops, then starts falling again, but more slowly.(C) suddenly shoots upward, and then starts falling again, but more slowly.(D) Suddenly shoots upward, and then starts falling again, eventually acquiring the same speed as before the chute opened.

The correct option is:
(C) suddenly shoots upwards, and then starts falling again, but more slowly.
With the help of a parachute, the parachutist increases contact area between the air and the falling body. The larger upward thrust due to the air provides an upward acceleration to the falling parachutist.
The upward thrust suddenly shoots the parachutist upward, relative to the one falling freely, and then the parachutist falls slowly over time.