Read the excerpt from Poe’s "The Fall of the House of Usher."His action was alternately vivacious and sullen. His voice varied rapidly from a tremulous indecision (when the animal spirits seemed utterly in abeyance) to that species of energetic concision—that leaden, self-balanced and perfectly modulate guttural utterance . . . during periods of his most intense excitement.Which short story element does Poe develop in the excerpt?