Many african americans during world war i
could not find work at all.
could not move to find work.
found work in rural areas.
found work in northern cities.

The correct answer is - found work in northern cities.

During World War I there was a huge shift in the population of the African Americans, when lots of them rushed to move to the northern part of the country, mostly in the cities, hoping that they will have a better life than in the southern part of the country were they were mainly concentrated until then. They did found work, and that was not hard to achieve, since there were lots of industrial facilities that were in need of labor force. The problem was that most of them got only low paying jobs in the factories, so their economic situation did not really improved as they were hoping for, but instead they were used as a cheap labor in the north.

a population change of 12.1%

hope this