The correct answer is b - China and the Soviet Union.
In the Pacific arena, the Japanese invasion of China and numerous European colonies in South East Asia led to mass slaughters, outbreaks of disease and continued guerrilla warfare. China lost a total of 10 million people, 75% civilians.
During Germany' s invasion of the Soviet Union in operation Barbarossa, it is estimated that a total of 20 million Russians died, half of whom were civilian. The Red Army later pushed the Germans back to Berlin.
