Once a carousel is in motion, the constant movement of the carousel horse around the center of the circle can best be described as a) acceleration; change in speed. b) velocity; speed plus direction. c) acceleration; change in velocity. d) speed; distance traveled over time.

C) acceleration; change in velocity.

Explanation:

When an object is moving around in a circulation motion with constant speed then even if the movement is constant still the velocity is changing at each point because of the change in the direction at each point. If the velocity is changing at each point then that means the object is accelerating.

But, in linear motion if an object has constant movement then the acceleration is considered zero because there is no change in the direction so velocity change is considered zero.

Since the carousel in this question is moving in the circular motion so it means that its direction is changing at each point which implies that its velocity is changing leading to acceleration.