A toy gun a spring of force constant `k`. When changed before being triggered in the upward direction, the spring is compressed by a distance `x`. If the mass of the shot is `m`, on the being triggered it will go up to a height of
A. (a) `(Kx^2)/(mg)`
B. (b) `(x^2)/(Kmg)`
C. (c) `(Kx^2)/(2mg)`
D. (d) `(K^2x^2)/(mg)`