Answer:
C: a movement of goods and people from Europe to the Americas and back again.
Explanation:
The Columbian exchange consisted in the exchange of both goods and people, between the two continents: Europe and the Americas.
The flow of people was mostly from Europe to the Americas, but in a few ocassions it ocurred the other way.
The flow of goods was mutual: American goods such as tomatoes, potatoes, and corn, found their way in Europe, while important European goods such as the horse, pigs, cattle, wheat and oat, also found their way in the American continent.
