Your answer will be 3). effect of mass media advertising. This is more of a demand, not really a supply.
The student used correlation not causation. There is a high correlation with gray haired residents and Florida. But the cause of graying hair is not living in Florida. It might be something totally different. It might be a coincidence that it so happens to be in Florida. The student needs more evidence to make such a leap in logic.
A iconoclast us someone who believes in using icons in worship