Answer: C Americans were asked to buy Liberty Bonds and the rationing of essential materials was instituted
Step-by-step explanation:
The United States was able to finance both World Wars in part by selling war bonds to her citizens. In WWI they sold Liberty bonds and in associating it with American victory, made it a symbol representative of one's patriotic duty.
As Europe was being devastated by war and could not produce much of its own food, the Americans can to step up and do more of that. This led to the rationing of essential materials.