The correct answer is the division of Germany among the Allied Powers.
During the Yalta Conference, the US, Soviet Union, and Great Britain, started to think about what a post World War II society would look like. One of the things discussed at this meeting was Germany. To ensure that Nazism and people like Hitler did not rise to power again after World War II, the Allied Powers agreed that Germany must be controlled by the Allied Powers. This is why Germany was split up into 4 different military zones after World War II, with each zone controlled by a significant member of the Allied Powers.
