I would assume that the answer is D: the way the author "speaks" to an audience on a page. We never truly know how the author feels until he/she shows us through his/her words. We really can't see this through conversations between characters, because often there will be characters that the author doesn't really "like" or wants to "dwell" upon, so often the conversations do not reveal much. The theme of the novel does convey a lot, but we still don't really know how the author feels about it. Themes are so hard to identify and everyone comes up with something different, so I would not see trying to find the author's voice in this option. Even though the writing can represent real people, it will not always represent the author. The best choice for me here is D. I hope that this helps and that that is the right answer!