In What Way Was Gustave Courbet's the Stone Breakers an Explicit

In what way was Gustave Courbet's The Stone Breakers an explicit political statement?

A) His elevated his lower-class subject to the heroic status afforded history painting.
B) He refused to exhibit it in the Salon and wrote a manifesto criticizing the academies.
C) He rejected academic conventions to idealize the subject.
D) He depicted an actual event that spawned violent protests outside the city of Ornans.