The answer is b] hydroelectric power
The people of Sumer are among the earliest denizens of Mesopotamia. By about 4000 BCE, the Sumerians had organized themselves into several city-states that were spread throughout the southern part of the region. These city-states were independent of one another and were fully self-reliant centers, each surrounding a temple that was dedicated to god or goddess specific to that city-state. Each city-state was governed by a Priest King.
the answer is c, books became easier to get a hold of.
Functional sees society as acting like an organism BECAUSE every aspect of society serves a specific function (like a cell, everything does something to contribute to the whole
