The statement that most accurately compares the atrocities committed by Nazi Germany and Imperial Japan during WWII is:
Both the Nazis and Japanese used racial superiority as a justification for the imprisonment and extermination of groups of people.
This statement reflects how both regimes operated under ideologies that promoted notions of racial superiority, which led to the widespread oppression and extermination of various groups. The Nazis specifically targeted Jews, Romani people, and others deemed "inferior" according to their racial ideology, while the Japanese military and government propagated ideas of superiority over other Asian peoples, leading to numerous atrocities in occupied territories.