How did U. S. participation in World War I contribute to its emergence as a world power in the early 20th century? Select all the correct answers.
A The U. S. weakened the Allied countries by making France, England and Russia reduce the size of their armies.
B The U. S. mobilized a large army and navy to help the Allies achieve victory.
The U. S. enjoyed a period of economic prosperity after the war.
D The U. S. played a strong leadership role in League of Nations actions in the postwar period.