Figure shows that particle A is projected ,from point P with velocity u along the plane and simultaneously another particle B with velocity v at an angle $\mathrm{\alpha }$ with vertical. The particles collide at point Q on the plane. Then 

• A

  $\mathrm{vsin}\left(\mathrm{\alpha }-{\mathrm{\theta }}_0\right)=\mathrm{u}$

• B

  $\mathrm{vcos}\left(\mathrm{\alpha }-{\mathrm{\theta }}_0\right)=\mathrm{u}$

• C

  $\mathrm{v}=\mathrm{u}$

• D

  None of these