If a stone is to hit at a point which is at a distance d away and at a height h (Fig.) above the point from where the stone starts, then what is the value of initial speed u if the stone is launched at an angle$\mathrm{\theta }$ ? 

• A

  $\frac{\mathrm{g}}{\mathrm{cos\theta }}\sqrt{\frac{\mathrm{d}}{2( \mathrm{dtan\theta }-\mathrm{h})}}$

• B

  $\frac{\mathrm{d}}{\mathrm{cos\theta }}\sqrt{\frac{\mathrm{g}}{2(\mathrm{dtan\theta }-\mathrm{h})}}$

• C

  $\sqrt{\frac{{\mathrm{gd}}^2}{ {\mathrm{hcos}}^2\mathrm{\theta }}}$

• D

  $\sqrt{\frac{{\mathrm{gd}}^2}{( \mathrm{d}-\mathrm{h})}}$