To a stationary man rain is falling on his back with a velocity 6 km/h at an angle 30' with vertical. To make the rain velocity appear vertical the man should move (1) Forward with a velocity 3 km/h (2) Forward with a velocity 3/3 km/h (3) Backward with a velocity 3 km/h (4) Forward with a velocity 213 km/h - from the ground.