Why was lenin's leadership crucial to the success of the russian revolution?

Not long after the Bolsheviks had seized power in 1917, Vladimir Ilyich Lenin filled out a bureaucratic questionnaire. For occupation, he wrote “man of letters.” So it was that a son of the Russian intelligentsia, a radical straight from the pages of Dostoyevsky’s novel The Possessed, became the author of mass terror and the first concentration camps ever built on the European Continent.

Ibelieve the answer is c