A boy is cycling such that the wheels of the cycle are making $120$ revolutions per minute. If the diameter of the wheel is $90\;cm$ , then the speed per hour with which the boy is cycling is _______ km / hr(approx)

Question

$(A) \; 15\;km/hr \\(B)\;16\;km/hr \\(C)\;20\;km/hr \\(D)\;22\;km/hr$