What happened in Russia in 1917 that led the United States to justify its involvement in World War I as a fight for democracy?
A) Russia signed a military defense treaty with France and Great Britain.
B) Russia signed the Treaty of Brest-Litovsk and made peace with the Germans.
C) Russian revolutionaries overthrew the Czar and established a provisional government.
D) Russian Bolsheviks, under Vladimir Lenin's leadership, toppled the provisional government.