Answer: C. Dramatic irony.
This is a case of dramatic irony. Irony refers to a rhetorical device in which what appears, on the surface, to be the case, is in fact radically different from what is actually the case. It often relies on the reader (or audience) knowing more than the characters. In this case, the irony is that Viola is explaining how women feel love by describing her own experiences. However, because she is dressed as a man, Orsino does not realize this.