The correct answer is logos. Logos is logical appeal, or the appeal to reasoning. Ethos is ethical appeal, or an attempt to make the speaker or writer appear trustworthy, and pathos is emotional appeal, or an attempt to make the reader feel strongly about the speaker or writer's topic. A harmatia, in literature, is a fatal flaw in a character, and has nothing to do with persuasion or rhetorical language, as far as I know.
Hope this helps!
