Answer:
D. The Eastern front turn into a stalemate.
Explanation:
Germany was the modern may of Europe before world war 1, with a developing and ground-breaking naval force intended to equal England, and ground powers far better than those of France and Russia.
It nearly worked as well. Toward the day's end they battled the gathered powers to a stalemate for a long time, and without the US would have most likely won with the breakdown of Russia to the upheaval.