Karl Marx developed a theory called historical materialism, which had a great influence in the field. In this theory, which emphasizes the importance of economic factors rather than thoughts and values in social transformation and can be defined briefly as “embracing history from a materialist point of view”, Marx specifically focuses on production. According to Marx, some social relations called production relations develop among the people participating in the production process in order to produce their social lives in the historical process. The correct answer is C.