Correct answer: C. Bolshevik Party
Explanation: The direct answer is C, the Bolshevik Party. Vladimir Lenin was the principal leader of the Bolsheviks during the Russian Revolution of 1917. To understand this, remember that Russia had disagreements within the socialist movement. The Bolsheviks, led by Lenin, demanded a disciplined revolutionary party and later took power in the October Revolution. Option A, the Menshevik Party, was a rival socialist group and was not Lenin's main party. Option B, the Conservative Party, is associated mainly with British politics, not Lenin's Russian revolutionary movement. Option C is correct because Lenin led the Bolshevik faction and its revolution. Option D, the Labour Party, is also mainly connected with Britain and was not Lenin's organization. Memory cue: Lenin, Bolsheviks, and the Russian Revolution belong together; the word Bolshevik should immediately suggest Lenin.