The approach known as Frankfurt School or Critical Theory, which first appeared in 1923, had also an important influence in the development of Marxism after the death of Marx. It is also known that theorists such as Max Horkheimer (1895-1973), Erich Fromm (1900-1980), Herbert Marcuse (1898-1979) and T.W. Adorno (19031969) had great contributions to the development of critical theory until the 1970s. The contributions of Jurgen Habermas (1929-) in the 1980s brought a new dimension to critical theory. Therefore, the correct option is C.