It's A
Irrigation was overused, the soil didn't get any rest (crop rotation is a younger invention), the result was salinization of the soil, which led to decline of Sumer.
Yes, as this would ensure more equal representation for the US's states and all territories which is occupied without much care. These territories would be able to become involved, allowing the people more freedom and more power, creating a better living situation for themselves and therefore bettering the US as a whole by creating a new area of opportunity.
Today's 'democracy' is more of a republic than anything. In ancient Greece, every citizen got a direct and equal vote, by casting stones into the pile that signified which side they were on. In today's democracy, the people don't get that much say
