The arrival of europeans and the resulting global exchange of people, animals, plants, and microbes—what scholars benignly call the more than ten thousand years of geographic separation, inaugurated centuries of violence, unleashed the greatest biological terror the world had ever seen, and revolutionized the history of the world.

The Columbian Exchange.

Explanation:

The Columbian Exchange refers to the trade of ideas, food, crops, and populations, as well as diseases and violence after Christopher Columbus arrived in the Americas in 1492.

The Columbian Exchange connected what was called the New World and the Old World, which included Europe and the entire Eastern Hemisphere, allowing the spread of diseases previously unknown to some communities, and started a long and violent process of colonization.

answer; a cost benefit analysis;