1 is C I think I'm not sure.
A. they have collapsed and returned to communist policies
Revise the articles of confederation.
Roaring Twenties! In France, since it was a period of mind-numbing fun to cope with the mass death, it's called "Années folles," or the crazy years.
Concert of Europe: Also known as the Congress System or the Vienna System after the Congress of Vienna, a system of dispute resolution adopted by the major conservative powers of Europe to maintain their power, oppose revolutionary movements, weaken the forces of nationalism, and uphold the balance of power.