Answer:
D. insisting that the Monroe Doctrine provided a valid justification for intervention.
Explanation:
Monroe Doctrine is the speech by the president of the United States in 1823, James Monroe who declared the foreign policy of the country in the western hemisphere and foreign involvement would not allowed. After the first world war, there was an increasing threat to get support for the neighbors of the U.S against the allies' cause and to restrict this Intervention in these countries would be justified by using Monroe doctrine.
The League of Nations was formed to unify many countries. It wasn't very efficient. The United Nations was essentially an improved version of the League of Nations.
Recognizing the sovereignty of the Vatican State.
The answer is b)to train ministers
I believe they became important members in the Cold War.
