What does an acceleration of zero indicate about an object's motion?

An acceleration of zero indicates that an object's velocity is constant, meaning that it is either at rest or moving with a uniform velocity. When an object is at rest, it doesn’t change its position over time, which means its acceleration is zero. Similarly, if the object is moving at a constant velocity, it is not speeding up, slowing down, or changing direction, which also results in zero acceleration.

Additionally, Newton’s first law of motion states that an object will remain at rest or move at a constant velocity unless acted upon by a net external force. Therefore, zero acceleration implies that the net force acting on the object is also zero, as there are no unbalanced forces causing a change in the object's state of motion.

In summary, when acceleration is zero, it encompasses all these scenarios: the object can either be at rest or moving steadily, and there is no net force affecting its motion. Thus, the option stating all of the above is the accurate and comprehensive choice.