3. The period between 1920 to the United States' entry into World War II is sometimes called
the age of

The period of time between 1920 and the U.S. entry into World War II has been called an Age of Isolationism, although that isn't 100% accurate. I mean, for one thing the U.S. sponsored a series of arms reduction negotiations that resulted in the Washington treaties limiting the number of battleships that a country could possess.

Explanation:

d is the best answer for this question.