The function \( h(t) = -16t^2 + 75t \) represents the height of a ball thrown into the air after \( t \) seconds. The notation \( h(5) \) indicates the height of the ball at \( t = 5 \) seconds.
Thus, \( h(5) \) represents the height of the ball 5 seconds after it has been thrown.
So, the correct response is: The height of the ball 5 seconds after it has been thrown.