Answer: Hello mate!
The velocity of the pony is constant in magnitude, so you may think that the pony is not acelerating, but you need to notice that the track has an ocal shape.
This means that the direction of the velocity is changing all the times, this mean that there is an "acceleration" changing the direction of the velocity, this is called centripetal acceleration, then the pony is accelerating around the track.
The right answer is C.
