How did racist and oppressive tactics used by fascist leaders in Germany and Italy contribute to the ultimate US Victory in World War 2?

A) Oppressive and Genocidal programs distracted German and Italian leaders, allowing a much smaller US force to overwhelm their armies.
B) Fascist tactics placed immense burdens on the people of Germany and Italy, prompting large-scale rebellions once American troops arrived in Europe.
C) Racist ideologies against non-whites promoted by german and Italian leaders led them to abandon Japan as soon as the united states entered the war.
D) Many of the scientists who contributed to the development of the atomic bomb were Germans and Italians who had fled fascist governments.