What happened during the Columbian Exchange?

a. Thousands of people from the Americas migrated to Europe.

b. Columbus returned to the Americas six times.

c. Spanish explorers traded food for gold in Latin America.

d. Plants, animals, diseases, and people moved among continents.

D) Plants, animals, diseases and people moved among continents during the Columbian Exchange. "The Columbian Exchange is defined as the widespread transfer of animals, plants, culture, human populations, technology and ideas between the American and Afro-Eurasian hemispheres in the 15th and 16th centuries, related to European colonization and trade (including African/American slave trade) after Christopher Columbus' 1492 voyage."