You didn't give us choices to choose from, but I think I can answer this nevertheless. Russia was in a bad way during the Great War (as it was called in those days). The people were starving as a result of famine in the country. The country didn't have the resources to feed its people, let alone be fighting a war in Europe. The Russian people were weary of the war and just wanted it to end.
The negative conditions faced in Russia also help explain why revolution took place during those years, beginning in 1917, and bringing the communist movement to power.