Which most accurately analyzes the impact that World War I had on the internal politics of Russia?

Responses
The loss of life and food shortages caused widespread social discontent, which forced the czar to abdicate.
The devastating losses to Ottoman forces led to the establishment of Islamic law in rural parts of Russia.
The Russian victories along the eastern front gave the Russian Provisional Government legitimacy.
The Allied alliance system collapsed and allowed the Bolsheviks to come to power.

The loss of life and food shortages caused widespread social discontent, which forced the czar to abdicate.