The correct answer is C) Social Democrats.
Although the Social Democrats were split into two opposing groups, the Bolsheviks and the Mensheviks, both had the goal of overthrowing the czar.
The Socialists suffered a split in November 1903, into two factions, the Bolsheviks and the Mensheviks. During the Second Congress of the Social-Democratic Labour Party of July 1903, had many different strong arguments for each of the delegates participating. The debates were harsh because the party had two clear factions: the Bolsheviks that were the majority and the Mensheviks, that were the minority.