Final answer:
Karl Marx's conflict theory suggests that capitalism is the main source of tension between social classes due to social differences between the rich bourgeoisie and the poor proletariat.
Step-by-step explanation:
Karl Marx's conflict theory suggests that capitalism is the main source of tension between social classes. According to Marx, capitalism creates a divide between the bourgeoisie (the owners of the means of production) and the proletariat (the workers who sell their labor).
This division is based on the unequal distribution of wealth and power, leading to social conflict. The concept of social stratification resulting from ownership and labor in capitalism is the subject of this question.