A Balloon Is 100 Metres Off the Ground and Rising

Multiple Choice

A balloon is 100 metres off the ground and rising vertically at the constant rate of 3 metres per second just as an automobile passes beneath it travelling along a straight, level road at the constant rate of 72 kilometres per hour. How fast is the distance between them changing one second later? (rounded to the nearest hundredth of a metre)

A) 6.76 metres per second
B) 43.71 metres per second
C) 20.22 metres per second
D) 10.00 metres per second
E) 1.28 metres per second