A ball of mass m is projected from the ground with an initial velocity u making an angle of $\theta$ with the
vertical. What is the change in velocity between the point of projection and the highest point? 

• A

  $u$ cos $\theta$  downward

• B

   $u$ cos $\theta$ upward

• C

   $u$ sin $\theta$ upward

• D

  $u$ sin $\theta$ downward