The electron of mass 0.9 x 10-30 kg under the action of a magnetic field moves in a circle of 2 cm radius at a speed of 3 × 10 ms-1¹. If a proton of mass 1.6 × 10-27 kg is to move in a circle of the same radius in the same magnetic field, then its speed will be
(1) 16.85 m/s
(3) 1.6375 m/s
(2) 1687.5 m/s
(4) 1.6875 × 10-³ m/s​