The right answer is Wealth was being distributed too unevenly in the United States.
With the emergence of the Industrial Revolution, a new system of production came into existence in the society and that was capitalism. The capitalistic system gave rise to two classes - owners’ class and workers' class. The capitalists were men of wealth, power and property and they started to exploit the workers. They committed injustice upon the workers' class as a result of which the atmosphere of unrest and displeasure got aroused in the workers' class. As a result, a Marxist criticism that best fit in this case would be one expressing how unjust is the distribution of wealth, so Wealth was being distributed too unevenly in the United States.