The years 1915-1940 saw the great african-american migration, when millions of african-americans migrated from the south to the north. how did world war i foster this massive migration?

While the army was at war, many jobs opened up that otherwise would not have. The Army took up many workers, and the arms industry expanded.

The south, in the meantime, was stagnating. Traditional employment in the south was working to capacity and the north looked like worthwhile greener pastures.

i would say your answer is a)

sorry if im wrong