The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
Compare the emergence of advanced Civilizations in Mesopotamia and South America with the four early river valley Civilizations. In contrast to the leaders of Mesopotamia Civilizations, Native American leaders lived in tribes and did not depend so much on agriculture like was the case of the early river valley civilizations that depending so much on the flooding of the rivers to have fertile soil in order to grow crops.
Native American leaders did not found city-states. They established tribes that lived hunting animals and fishing, so they could feed their families.