The answer is D) The depopulation of the Americas, the overall effect was an increased population worldwide
When the Taino gathered on the shores of San Salvador Island to welcome a small party of foreign sailors on 12 October 1492, they had little idea what lay in store. They laid down their weapons willingly and brought the foreign sailors—Christopher Columbus and his crewmen—tokens of friendship: parrots, bits of cotton thread, and other presents. Columbus later wrote that the Taino “remained so much our friends that it was a marvel.”
A year later, Columbus built his first town on the nearby island of Hispaniola, where the Taino numbered at least 60,000 and possibly as many as 8 million, according to some estimates. But by 1548, the Taino population there had plummeted to less than 500. Lacking immunity to Old World pathogens carried by the Spanish, Hispaniola’s indigenous inhabitants fell victim to terrible plagues of smallpox, influenza, and other viruses.
The population of African and Eurasian peoples in the Americas grew steadily, while the indigenous population plummeted. Eurasian diseases such as influenza, bubonic plague and pneumonic plagues, yellow fever, smallpox, and malaria devastated the Native Americans, who did not have immunity to them. Conflict and outright warfare with Western European newcomers and other American tribes further reduced populations and disrupted traditional societies. The extent and causes of the decline have long been a subject of academic debate, along with its characterization as a genocide.[2]
Populations in other parts like in Europe benefited of the products imported by Europeans like corn, potatoes, etc.