The correct answer is - D. Farms could support larger groups of people, which led to increased population growth.
Alongside the rivers farming took on a step up in the production of food. The rivers were flooding each year and with it they were making big deposits of fertile material around them. This meant that the soil was of great quality each year and the people that were living there were able to produce big amounts of food, very often even surplus of food. This allowed the river valley civilizations to be able to prosper and also focus on other things apart from sheer survival, so cities started to emerge, the architecture started to develop, the basis of sciences etc.
In Athens only adult males with military training could vote and they voted for everything unlike in us citizens age 18 and above can vote and in US the people elect representivites to represents them.
