Given what you know about the geography and chronology of the chavin and nazca, what might explain the fact that the chavin and nazca both used underground aqueducts to transport water?

In both cultures, the basis of their economy was agriculture. But this was very difficult to carry out due to the geographical conditions in which they were. They were located in an area where the climate was very dry, the land was scarce and there was very little water to irrigate those lands. Both Chavin and Nazca solved this by using underground aqueducts to transport water and, therefore, irrigate the crops permanently. Then, the most important reason why they resorted to this mechanism is the lack of water to irrigate the crops.

answer; i believe the correct answer is (the willamete valley);

a system of cooperative federalism emerged, as the powers of the federal government expanded.