An automobile moves on a road with a speed of 54 km h. The radius of its wheels is 0.45 m and the moment of inertia of the wheel about its axis of rotation is 3 kg m. If the vehicle is brought to rest in 15s, the magnitude of average torque transmitted by its brakes to the wheel is -2 (a) 8.58 kg m s (c) 2.86 kg m s -2 (b) 10.86 kg m s (d) 6.66 kg m s