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 exemplifies a clear instance of class struggle, as it reflects the conflict between the lower classes (in this case, women representing the working class) and the ruling powers (the monarchy) over essential needs, highlighting the tensions and struggles that Marx emphasizes in his analysis of society's history. The other options, while significant historical events, do not directly illustrate the theme of class struggle as clearly as this one does.