If the net force on an object is zero, we can definitely say that the object is moving with constant velocity.
This conclusion stems from Newton’s first law of motion, which states that an object at rest will stay at rest, and an object in motion will continue to move at a constant velocity unless acted upon by a net external force. Hence, a net force of zero indicates that either the object is at rest or it is moving uniformly.
However, while we can confirm constant velocity, we cannot assert that the object is at rest (option c), nor can we claim that the object is non-existent (option d) because a net force of zero doesn’t imply anything about the existence of the object itself. Therefore, the correct interpretation of a zero net force is that the object maintains its state of motion, which translates to moving with a constant velocity.