What actions did the Allied countries take after World War II to prevent future wars? Select three correct answers.

A. They fixed the damage in Pearl Harbor.

B. They conducted trials for war crimes.

C. They removed all troops that were overseas.

D. They raised tariffs on trade with Axis forces.

E. They signed peace treaties with many countries.

F. They created the United Nations.
In my opinion, E and F are good options but I don't know the third.