The answer is D: writing or speech that offers insights into society.
Social commentary is a form of rhetoric aimed at informing the population or the audience of a particular and problematical societal issue, aiming at the promotion of change, most notably in the direction of justice. In this regard, social commentary offers insights into society based on an acute and usually critical point of view. Some great examples of social commentary can be found, for example, in the writings of Rabelais or Jonathan Swift.