Which of the following best summarizes the impact that farming had on the
development of early river valley civilizations?

A. Farms could support larger groups of people, which led to
increased population growth.

B. Farming produced a surplus of food, which allowed people to form
less permanent settlements.

C. Fewer people were needed to support each farm, so the
population near farms decreased.

D. Fewer farms were needed to produce enough food, so many
people had no work to do.