I believe your best answer would be D. "Well prepared industrially but not militarily". The United States in this time was an economic powerhouse, and a golden age was right around the corner. We had the manufacturing capabilities to fight in a world war, we were in fact already supplying countries like the U.K with guns and ammunitions. However our military was another matter, if memory serves our standing army was only twenty thousand strong. So whenever we entered the war it was up to general "Black Jack" Perishing to raise the standing army and transport all those men over to Europe, before Germany could move it's troops from the Eastern front to the western front after Russia just pulled out of the war. He ended up in just a few months with the help of a draft raise the army to over a million men and have a majority of them in Europe before the German reinforcements could arrive. A total war policy was used in America until the wars end saying to conserve everything and do your part.
Hope this helps you!