What Does the Term Columbian Exchange Refer To

What does the term Columbian exchange refer to?

A) the peaceful exchange among Europeans and Native Americans of native edible plant species
B) the spread of European notions and technologies of warfare to Native Americans, who never engaged in massive violent campaigns prior to the 1500s
C) the spread of people, resources, products, ideas, and diseases between the Eastern and Western hemispheres after contact
D) the exchange of culture that occurred among Native Americans and Europeans that eventually led to the first great civilizations in the Americas and, in Europe, the first classless societies
E) the general reciprocity that characterized the relationship between Europeans and Native Americans during the first 15 years after initial contact