The correct answer is (b). Karl Marx is the one who has given the theory of ‘surplus value’.
Surplus value is the difference between the value of goods produced by workers and the wages they are paid. Marx argued that capitalists exploit workers by taking this surplus value for themselves.
Max Weber was a German sociologist who is best known for his work on bureaucracy, rationalization, and the Protestant work ethic. Martin Heidegger was a German philosopher who is best known for his work on existentialism and phenomenology. J. Habermas is a German philosopher and sociologist who is best known for his work on communicative action and the public sphere.
Weber, Heidegger, and Habermas all made significant contributions to social theory, but none of them developed a theory of surplus value.