As the United States Drifted to War from 1939 Through

As the United States drifted to war from 1939 through 1940,and American industries shifted from domestic to war manufacturing,black workers

A) found their opportunities for economic advancement blocked by rigid anti-black policies and the hostility of white workers.
B) gained unprecedented access to skilled jobs on nearly the same scale as white workers.
C) drove many white workers out of the industries because employers preferred to hire blacks,whom they felt they could pay lower wages.
D) were lured from distant lands by employers in industrial centers like Chicago and San Francisco who were desperate for any workers they could acquire.