Hail stones falling vertically with a speed of 12√3m/s hits the wind screen which makes an angle 30º with the horizontal. If car is running at velocity v(in m/s) so that the driver find the hailstones striking perpendicular to the wind screen. Find the value of v/2?

(A) 6 m/s

(B) 8 m/s

(C) 5 m/s

(D) 9 m/s