The Columbian Exchange refers to the exchange of plants, animals, diseases, and technologies between the Americas and the rest of the world after Columbus voyages.

• A. The trade routes between Europe and Asia in the 15th century
• B. The exchange of plants, animals, diseases, and technologies between the Americas and the rest of the world after Columbus voyages
• C. The exchange of scientists between universities
• D. The spread of agricultural equipment

Answer: (B)

The concept being tested is how cross-hemisphere exchanges transformed ecosystems and societies after contact with the Americas. The Columbian Exchange describes the transfer of plants, animals, diseases, and technologies between the Americas and the rest of the world following Columbus’s voyages, opening up global connections that reshaped diets, farming, and populations. This description fits best because it names all four categories and the Atlantic-hemisphere scope, not just a trade route or a narrow form of exchange. For example, crops like potatoes and maize moved to Europe and Asia, while horses and cattle were introduced to the Americas; diseases such as smallpox spread to indigenous populations, and Europeans brought new tools and technologies. Other options either focus on a different, pre-Columbian trade network (between Europe and Asia), on exchanges of people rather than goods and crops, or on a narrow aspect like equipment without acknowledging the broad, transatlantic transfer.