How do historians define the modern era? A. The period in history when people first became capable of communication
B. The present time period in which people share information using technology.
C. The period in world history that began after the end of the World War II
D. The period of world history that began after the end of the middle ages in Europe.

secretly cooperate with one another.

(d) rivers.

explanation:

civilizations developed around rivers because their waters provided places to hunt and fish. also, as the rivers flooded, the lands around them became fertile. this allowed them to support farming. this is especially true of the nile river, which flooded the same time each year.

the answer to this question is the third option. hope this

answer; (c) slaves brought to the americans from africa;