The correct answer is C) People moved to cities that had built up industries for war production.
The war affected the migration of workers in the United States in that People moved to cities that had built up industries for war production.
Many people moved from rural areas to work in factories as well as many immigrants went to the larger cities where the war industries were located to get the jobs they much needed. Many Americans enlisted in the war and were sent to Europe to fight at the war front. Industries were in need to produce war supplies and weaponry so they hired Immigrants, farmers, African Americans, and women.