According to Karl Marx,the most important social structure in any society is the system of ____.

A) class relations
B) government
C) social institutions
D) moral order
E) authority

According to Karl Marx's theory of historical materialism, the most important social structure in any society is the system of class relations. Marx believed that society was divided into two primary classes - the bourgeoisie (the capitalist class who owned the means of production) and the proletariat (the working class who sold their labor to the bourgeoisie). He argued that the struggle between these two classes is the driving force behind social change and that class conflict would ultimately lead to the overthrow of capitalism and the establishment of a socialist society. Thus, class relations are seen as the fundamental social structure upon which all other social relations are built.