After World War II the American Public Favored Continued International

After World War II the American public favored continued international engagement much more than they had after World War I. Why?

A) They feared an economic crisis similar to the one that occurred after WWI.
B) There was an opportunity for huge corporate profits from foreign investment.
C) As the wealthiest nation on earth, Americans felt it was their duty to help.
D) All these answers are correct.