I believe the correct answer is: C) Content describes what is written; style describes how it is written.
In literature, content refers to what is described in a literary work – the story, theme, message that author wants to convey, and style describes the ways that the author uses words — word choice, sentence structure, figurative language etc, and can be used as a marker for a certain author. Therefore, the correct option would be content describes what is written; style describes how it is written.