What effect did the fall of the Russian Empire have on the allied war effort during World War I?

A) The Russian Revolution caused Allied powers to fight a two front war, in Russia and in Europe.

B) The Russian Revolution caused the war to end sooner because so many soldiers died in the Revolution.

C) The new Russian government pulled all troops from the war, creating a troop deficit on the allied front.

D) The new Russian government refused to surrender to the central powers, preventing the war from ending sooner.