The component of vertical and horizontal velocities depends upon the initial speed and the angle made by football with the horizontal. The reasons given in part (b) is correct. As the time taken by football to cover the distance will be calculated using vertical component of velcoity therefore, if the vertical velocity is less than the time taken by the football will also be less. Also, the horizontal distance covered by the ball will depend upon the time.
Therefore, the reasons of part (b) is correct.