Answer:
C. an executive order issued by President Roosevelt.
Step-by-step explanation:
The national defense industry was prohibited from engaging in racial discrimination when executive order 8802 was enacted on June 25, 1941 by President Franklin D. Roosevelt. This order helped eliminate racial discrimination, and was an important step toward ending discrimination in all government employment practices. This allowed African Americans to benefit from an industry that had created millions of new jobs recently due to the military buildup that took place during WWII.