What Was the Fundamental Difference Between International Communism Under Stalin

What was the fundamental difference between international communism under Stalin and national socialism under Hitler?

A) Stalin promoted the ideal of promoting a better world for all the world's downtrodden while Hitler only championed the Germans.
B) Stalin was in favor of centralized economic government control and Hitler preferred economic liberty.
C) Stalin wanted freedom for the peasants and Hitler was in favor of freedom only for the upper classes.
D) Stalin crushed all political opposition while Hitler allowed opposition parties to exist in Germany.
E) Stalin opened up membership in the Communist Party to all citizens while Hitler preferred to keep the National Socialist to a ruling elite.