The statement that best supports Karl Marx's argument that "The history of all hitherto existing society is the history of class struggles" is:
Women led a march on the Palace of Versailles to demand cheaper bread prices.
This event illustrates a clear instance of class struggle, as it reflects the economic frustrations of the lower classes (represented by women, who were often responsible for providing for their families) against the ruling class or elite, highlighting the conflicts and tensions that Marx emphasized in his analysis of societal history. The march was a reaction to the economic disparities and struggles experienced by the common people in contrast to the privileges enjoyed by the monarchy and aristocracy.