The answer is D.
extra wording :)
Population masses wanting a change, political freedom, and desires for ethnic, nationalist self-governance are the reasons for a revolution. Through this unit, you will find out how many people wanted change and freedom from the abusive government. They want to improve their country and their liberty.
The landscape, being mostly very flat, cause many Native American societies to be spread out over significant portions of land, while the climate made them have to adapt to a variety of temperatures. The resources forced them to rely heavily on corn and fish do the inability to plant other types of food.
