Nations get significant advantages if they have a single, valuable, natural resource, with little downside risk

What best describes the role of the United States in World War I?

a. The U.S. entered World War I as soon as it started. b. The U.S. was a neutral moderator throughout the war. c. The U.S. entered the war on the side of Russia and opposed Austria Hungary. d. U.S. business suffered severe financial losses during the war.

Using your own words, describe the law of increasing opportunity costs. Be sure to explain why this phenomenon occurs and how it helps to contribute to the shape of the production possibilities frontier