Which of These Was Among the Negative Consequences of the Columbian

Which of these was among the negative consequences of the Columbian exchange of animals, people and crops between the continents?

A) It restricted the work of missionaries who had no immunity to the diseases of the Indians.
B) It caused the European monarchs to curtail future voyages to the Americas because of the lack of monetary support.
C) It encouraged the Spanish to give up their conquest for gold and silver and instead exploit the fishing grounds off the coast of Maine.
D) It increased the profitability of the slave trade.