When the tension becomes equal to Sue's weight, she will continue downward at constant speed.
Option C
Explanation:
It’s a simple and easy problem on physics. Here the frame of reference is the person Sue herself. She is going down the rope and the tension at a point on the rope is the weight of Sue herself. So at that point the force acting on Sue is her weight which is going downwards.
But it’s cancelled by the equal force that is the tension on the rope. At that particular point there’s no external resultant force that’s acting on Sue. So the speed at which Sue was descending remains constant. Â