The correct answer is option 4: Marxism. "Historical materialism" is a key concept in Marxist theory. It is the belief that the economic system and material conditions of a society are the primary drivers of social development and change. Marxism argues that the struggles between different social classes, specifically between the bourgeoisie (capitalist class) and the proletariat (working class), are the impetus for historical progress and social transformation.

Option 1, Capitalism, is incorrect because historical materialism is a critique of the capitalist system, rather than a tenet of it. While capitalism is based on the private ownership of the means of production, Marxism seeks to abolish this system and establish a classless society.

Option 2, Fabian socialism, is incorrect because historical materialism is not a specific tenet of this political ideology. Fabian socialism focuses more on gradual social reform through democratic means rather than the revolutionary vision of Marxism.

Option 3, Liberalism, is incorrect because historical materialism is not a core principle of liberalism. Liberalism emphasizes individual rights, free markets, and limited government intervention, which differ from the central tenets of historical materialism.

In summary, the correct answer is option 4, Marxism, as historical materialism is a fundamental concept in Marxist