In most early civilizations, people were able to grow a surplus of food and to manufacture local specialty items such as pottery. What was one result of these activities?
A.People in widely separated geographical locations developed a system of trade.
B.People became more isolated because they had no need to associate with other groups.
C.People exchanged new ideas and developed a system of government centered around democratic principles.
D.People became more warlike because they raided their neighbors for products they could not make themselves.