Scholars are not sure why Classic Maya civilization collapsed. Three theories are outlined below. Theory 1: City populations grew too fast for the farms to produce enough food. Theory 2: Warfare among Maya city-states increased until it was out of control. Theory 3: Outside invaders from central Mexico helped to destroy Classic Maya civilization. • For each theory, suggest one argument or piece of evidence that might support the theory. • For each theory, suggest one question historians or archaeologists could research that would help them decide whether the theory is likely to be correct.