Answer:
The correct answer is - At the maximum height, the velocity and acceleration vectors are perpendicular to each other.
Step-by-step explanation:
When the football reaches maximum height, then the vertical component of velocity will be zero and therefore the only component of velocity left will be the horizontal component, and acceleration of the object will be downward, due to gravity.
So at the maximum height, there is horizontal velocity only which means velocity is horizontal and acceleration is vertical thus, the velocity and acceleration are perpendicular to each other.