The Columbian exchange of crops affected both the Old World and the New. Amerindian crops that have crossed oceans—for example, maize to China and the white potato to Ireland—have been stimulants to population growth in the Old World. The latter’s crops and livestock have had much the same effect in the Americas—for example, wheat in Kansas and the Pampa, and beef cattle in Texas and Brazil. –Alfred W. Crosby
"The Columbian Exchange”
The Columbian exchange resulted in

A)benefits to populations native to the Americas through the introduction of a wide variety of new subsistence crops and livestock, with few negative consequences.
B)mostly negative consequences for populations in Europe, Africa, Asia, and the Americas due to widespread communication of disease.
C)the decimation of European populations due to the transfer of contaminated foodstuffs and the spread of unknown diseases from the Americas.
D)population booms in parts of Europe and Asia due to the introduction of new staple subsistence crops from the Americas.