Final answer:
The best explanation for the change in the population of enslaved Africans from 1601 to 1800 is the increased demand for slave labor in agriculture, especially for sugar and tobacco production in the New World.
Step-by-step explanation:
The change in the population of enslaved Africans from 1601 to 1800 can best be explained by a) Increased demand for slave labor in agriculture. This period saw a vast expansion of agricultural economies in the New World, particularly in the production of cash crops such as sugar and tobacco. To meet this demand, Europeans increasingly relied on the labor of enslaved Africans, resulting in the Transatlantic Slave Trade accelerating. For example, the English crown chartered the Royal African Company in 1672 to transport enslaved African people to the English colonies, resulting in approximately 350,000 Africans being moved from their homelands over the next four decades.
As sugar became more popular in Europe, the demand for enslaved laborers grew in Brazil and the Caribbean, which accounted for about 80 percent of the enslaved Africans brought to the Americas around the turn of the eighteenth century. The intense need for labor to exploit the natural wealth of the Americas made acquiring enslaved Africans through trade with West African kingdoms the primary method of sourcing labor.