When a scientist says an object is "at rest," the most accurate interpretation is:
The object is not moving relative to its surroundings.
This means that, from the perspective of an observer or a reference frame, the object does not change its position over time. While it's true that there may be forces acting on the object, as long as the net force is balanced (i.e., the forces are equal and opposite), the object can still be at rest. The other options provided may mention aspects of forces or motion but do not accurately define what it means for an object to be at rest in the context of physics.