A Football Is Kicked at an Angle $\theta$ With Respect to the Horizontal

A football is kicked at an angle $\theta$ with respect to the horizontal. Which one of the following statements best describes the acceleration of the football during this event if air resistance is neglected?

A) The acceleration is zero m/s² at all times.
B) The acceleration is 9.8 m/s² at all times.
C) The acceleration is zero m/s² when the football has reached the highest point in its trajectory.
D) The acceleration is positive as the football rises, and it is negative as the football falls.
E) The acceleration starts at 9.8 m/s² and drops to some constant lower value as the ball approaches the ground.