SAT US History Practice Question

Why did the writer Gertrude Stein describe Ernest Hemingway, F. Scott Fitzgerald, and other artistic and literary Americans as a "lost generation" during the 1920s?

1. A.They preferred to live in Europe, not the United States.
2. B.They had fought recently on the losing side in World War I.
3. C.They were disillusioned by the experience of World War I.
4. D.They had lost all feeling of American patriotism.
5. E.They despised society and lived isolated lives.