People in the south used slaves because their economy was focussed on things like cash crops (tobacco, cotton, etc.) These crops required a lot of work so farmers and plantation owners could not do it by themselves. So by using enslave persons they could harvest more crops, sell more, make more money, and in return boost the southern economy.
I have no clue of "which of the following" because i cannot see the answers but,
The Great Migration, or the relocation of more than 6 million African Americans from the rural South to the cities of the North, Midwest and West from 1916 to 1970, had a huge impact on urban life in the United States. Driven from their homes by unsatisfactory economic opportunities and harsh segregationist laws, many blacks headed north, where they took advantage of the need for industrial workers that first arose during the First World War. As Chicago, New York and other cities saw their black populations expand exponentially, migrants were forced to deal with poor working conditions and competition for living space, as well as widespread racism and prejudice. During the Great Migration, African Americans began to build a new place for themselves in public life, actively confronting economic, political and social challenges and creating a new black urban culture that would exert enormous influence in the decades to come.
