A ball is thrown at angle $\mathrm{\alpha }$ (${90}^{\mathrm{o}} > \mathrm{\alpha } > \mathrm{\theta }$) on inclined plane as shown in figure. The minimum speed

• A

  $\mathrm{u} \cos \mathrm{\alpha }$

• B

  $\mathrm{u} \cos \mathrm{\theta }$

• C

  $\mathrm{u} \cos (\mathrm{\alpha }-\mathrm{\theta })$

• D

  zero