#### Answer

( c)

#### Work Step by Step

Initial velocity of the moped is 0 km/h while its final velocity is 20 km/h. So the change in velocity is 20 km/h.
Initial velocity of the car is 80 km/h while its final velocity is 90 km/h. So the change in velocity is 10 km/h.
Since the time elapsed for the moped is double the time elapsed for the car, the acceleration for both the vehicles is the same. Therefore, the answer is (c).