The distance of closest approach of an alpha particle is d when it moves with a speed V towards nuc

. The distance of closest approach of an alpha particle is d when it moves with a speed V towards a
nucleus.
Another alpha particle is projected with higher energy such that the new distance of the closest approach is d/2. What is the speed of projection of the alpha particle in this case?
(A) V /2 (B) √2 V (C) 2 V (D) 4 V