The answer is d have a good day
The answer is B increased trade with others because when they traded with others they made money to make more houses and kept on selling crops that people wanted make a lot of money to build cities and buildings.
It’s (b) sorry for answering late
The correct answer is "A: The Great Migration".
The Great Migration was the relocation of more the 6 million African Americans from the rural and urban areas of Southeastern United States (the states of the former Confederacy) to urbanized locations in the northeast, midwest, and west of the country. This dramatically changed the population distribution of African Americans, as 90% of their total population lived in the Southeast prior to this policy but when it ended 50% would live in the designed areas for relocation.
B - Slave revolts.
The revolt of Spartacus, which was also the most famous slave uprising in the history of the Roman Empire, lead to questions about the usefulness and effectiveness of the current governmental system in Rome. This, along with other factors, made them plunge into a crisis which ended through the transition to an empire.