A particle is projected in `xy` plane with `y`-axis along vertical, the point of projection is origin. The equation of the path is `y=sqrt3x-g/2x^(2)`.where `y` and `x` are in `m`.Then the speed of projection in `ms^(-1)` is
A. 2
B. `sqrt3`
C. 4
D. `sqrt3/2`