The correct answer is B. Karl Marx
Step-by-step explanation:
Karl Marx was a German economist and sociologist mainly known for his proposals and theories in different fields. In terms of sociology, Karl Marx is mainly known for purposing the Conflict Theory in which he stated the history of society and humanity has been characterized by conflict especially by an eternal conflict between the different classes in society that struggle to get political power. Additionally, according to this proposal of class struggle Karl Marx believed it was class struggle and conflict one key factor for the development of the evolution of societies as over time the class that held the power changed. Therefore, the person that believed the history of society was one of class struggle and who proposed a theory based on this was Karl Marx.