Which of the following best summarizes the impact that farming had on the development of early river valley civilizations?
a. fewer people were needed to support each farm, so the population near farms decreased.
b. farming produced a surplus of food, which allowed people to form less permanent settlements.
c. fewer farms were needed to produce enough food, so many people had no work to do.
d. farms could support larger groups of people, which led to increased population growth.

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.

the effect of the ming leaders banning ships with more than two masts was that there was no further construction of ships masts, because there was a surplus. ming emperors disallowed foreign exploration