1: Each graph would represent how much time the boy scout takes to raise the flag.
2: Graph C is most realistic because the boy scout could face wind resistance, he could lose grip of the pulley momentarily, or his hands could slide on the pulley. This causes a variation of height as time goes by. But when the flag reaches the top of the pull, the height would stop increasing.
3. Graph F is the most unrealistic because there is no way the boy scout can pull the flag to the top of the pole in one second or one unit of time.