The correct answer is: B. Karl Marx.
Karl Marx was a German philosopher, economist, historian, sociologist, political theorist, journalist and socialist revolutionary. Born in Trier, Germany, Marx studied law and philosophy at university. He married Jenny von Westphalen in 1843. Due to his political publications, Marx became stateless and lived in exile in London for decades.
Marx's theories about society, economics and politicsâcollectively understood as Marxismâhold that human societies develop through class struggle. In capitalism, this manifests itself in the conflict between the ruling classes (known as the bourgeoisie) that control the means of production and the working classes (known as the proletariat) that enable these means by selling their labor power in return for wages.
Marx argued that capitalism would inevitably produce internal tensions which would lead to its destruction. Just as capitalism replaced feudalism, he believed socialism would, in its turn, replace capitalism, and lead to a stateless, classless society called pure communism.
Marx's thought has informed much of subsequent intellectual history, and his ideas are still debated and analyzed today.
Lenin was a Russian revolutionary, politician, and political theorist. He served as head of government of Soviet Russia from 1917 to 1924 and of the Soviet Union from 1922 to 1924. Under his administration, Russia and then the wider Soviet Union became a one-party communist state governed by the Russian Communist Party. Ideologically a Marxist, he developed political theories known as Leninism.
J. S. Mill was a British philosopher, economist, and civil servant. He was an influential contributor to social theory, political theory, and political economy. He has been called "the most influential English-speaking philosopher of the nineteenth century".
David Ricardo was an English economist, stockbroker, and politician. He was one of the most influential of the classical economists, and is best known for his theory of comparative advantage.