The correct option is A
Isolationism is a doctrine practiced by the United States during a large part of its history with the objective of not intervening in external affairs that did not pose a real threat to their country. The United States managed to maintain a state of political isolation throughout the 19th century and the first part of the 20th. Few nations have been able to maintain such a position for such a long period of time. Historians argue that it is largely due to geographical reasons, given the physical distance between Europe and the USA. UU The beginning of the twentieth century brought with it problems that occurred in Europe and the Pacific, and this would end in large part with the isolationist feelings of the United States.