What occurs to an object if the net force acting upon it is zero?

When the net force acting on an object is zero, it indicates that all forces acting upon the object are balanced. According to Newton's first law of motion, an object will remain in its state of motion unless acted upon by a net external force. Therefore, when the net force is zero, the object has two possibilities: it can either be at rest or continue to move at a constant velocity.

If the object is already at rest, it will remain at rest as there is no unbalanced force to change that state. If the object is in motion, it will continue to move consistently in a straight line at the same speed, as no net force is acting to change its state of motion.

This understanding solidifies why the correct choice is that the object will either remain at rest or move at a constant velocity.