A ball was thrown upward into the air. The height, in feet, of the ball above the ground t seconds after being thrown can be determined by the expression -16t^2 + 40t + 3. What is the meaning of the 3 in the expression?

A.
The ball was thrown from a height of 3 feet.

B.
The ball took 3 seconds to reach its maximum height.

C.
The ball took 3 seconds to reach the ground.

D.
The ball reached a maximum height of 3 feet.