The Way Political Positions Are Now Commonly Described as Left

The way political positions are now commonly described as left, right, or center comes from

A) the fact that Karl Marx and other prominent radicals have been left-handed.
B) the anarchists' attempt to overthrow the British government in 1848.
C) seating arrangements in the National Assembly during the French Revolution.
D) Karl Mannheim's attempt to distinguish central from peripheral ideologies.
E) soccer, where the most "radical dudes" always play the left-wing.