Final answer:
Karl Marx described religion as 'the opiate of the people' and the correct answer is D) All of the above, as he also mentioned that religion is the sign of the oppressed, the heart of a heartless world, and the soul of soulless conditions.
Step-by-step explanation:
Karl Marx is indeed famous for his statement that "religion is the opiate of the people." This phrase encapsulates his critical view that religion serves to dull the pains of oppression and provide a false sense of comfort to the working class. Going further, Marx's statement also included the lines that religion is "the sign of the oppressed creature," "the heart of a heartless world," and "the soul of soulless conditions." Therefore, the correct answer to the student's question is D) All of the above. Marx's analysis suggests that religion is an ideological tool that not only soothes psychological pain but also reinforces the economic and social inequalities by dissuading the working class, or the proletariat, from advocating for systemic change in the here and now by focusing on an afterlife promise.