Read the excerpt from Robert Louis Stevenson’s Strange Case of Dr. Jekyll and Mr. Hyde:

Strange Case of Dr. Jekyll and Mr. Hyde

by Robert Louis Stevenson (excerpt)

I saw that, of the two natures that contended in the field of my consciousness, even if I could rightly be said to be either, it was only because I was radically both; and from an early date, even before the course of my scientific discoveries had begun to suggest the most naked possibility of such a miracle, I had learned to dwell with pleasure, as a beloved day-dream, on the thought of the separation of these elements.

Which theme is portrayed in this passage?

A.
keeping up appearances in society
B.
science versus nature
C.
duality of human nature
D.
deception and disguise

In the excerpt, he talks about the "two natures" and then goes on at the end to talk about how he might want to separate the two elements. Duality means the two different sides. This best fits the passage. He doesn't refer to appearances at all. He also does not speak of science versus nature, but rather how his scientific discoveries help him understand nature. He also does not intend any deception or disguise by exploring the two elements of human nature.