The path followed by a body projected along y axis is given by $y=\sqrt 3 x-\large\frac{1}{2}$$x^2$. If $g=10 m/s^2$ Then initial velocity of projectile is

Question

$$(a)\;3 \sqrt {10} \; m/s \quad (b)\;2 \sqrt {10} \;m/s \quad (c)\;10 \sqrt {3} \;m/s \quad(d)\;10 \sqrt {2} \; m/s$$