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Answer:
D. The introduction of the slave trade to the Atlantic World.
Step-by-step explanation:
Source 1 presents the beginning of the African slave trade, also known as the transatlantic trade, which allowed that during 1450 to 1750 a large number of African slaves were bought at very low prices and transported to different parts of the world, mainly to the American continent, to be part of the workforce of the farms in European colonies spread across the continent. Most of these slaves came from West Africa and were sold by other Africans, but it was common for Europeans to sail to Africa and capture slaves with their own hands to be sold on the American continent, which was more profitable for the sellers.