Final answer:
The football's horizontal velocity at its highest point is the same as its initial horizontal velocity because horizontal velocity remains constant when air resistance is negligible.
Step-by-step explanation:
When a football is thrown on a long pass, the horizontal velocity at the ball's highest point compared to its initial horizontal velocity is (c) the same. This is because horizontal velocity is only affected by air resistance, which is typically negligible in such cases, meaning that the horizontal component of the velocity remains constant throughout the trajectory of the pass. The vertical velocity, on the other hand, would be zero at the highest point due to the influence of gravity.