The equation of trajectory of a projectile is given by $y=x -\large\frac{x^2}{100}$ Find velocity of projection .

Question

$\begin{array}{1 1}(A)\;\frac{1}{100} \\(B)\;10 \sqrt {10} ms^{-1} \\(C)\;\frac{1}{300}\\(D)\;2 \end{array}$