What is the "columbian exchange"?
a. the exchange of scientific discoveries and inventions between the old and new worlds
b. the exchange of plants, animals, and germs between the old and new worlds
c. the exchange of weapons between the old and new worlds
d. the exchange of seafaring technology between the old and new worlds

B. the exchange of plants, animals, and germs between the Old and New Worlds

Explanation:

With contact between Europe and the New World, natural resources flowed between the continents. This unintentional trade has been called the Columbian Exchange. The tradeoff was not always fair. Maize (corn) from Mexico quickly became a precious crop across Europe and Asia. Smallpox from Europe was an unfortunate result of contact between people of the Americas and Europe. Still, this relationship helped transform the world into the place we know today