In a video game, a flying coconut moves at a constant velocity of 20 meters/second

In a video game, a flying coconut moves at a constant velocity of 20 meters/second in the positive direction. The coconut hits an obstacle and moves in the opposite direction with a constant velocity of 10 meters/second. What’s the change in velocity of the coconut? A.
-30 m/s
B.
-10 m/s
C.
10 m/s
D.
30 m/s