What is the author satirizing in this passage?

I said there was a society of men among us, bred up from their youth in the art of proving by words multiplied for the purpose, that white is black, and black is white, according as they are paid. To this society all the rest of the people are slaves.
(from Gulliver’s Travels by Jonathan Swift)
A.
philosophers
B.
lawyers
C.
public service
D.
literature