Read this stanza from "The Raven" by Edgar Allan Poe. Once upon a midnight dreary, while I pondered, weak and weary, Over many a quaint and curious volume of forgotten lore— While I nodded, nearly napping, suddenly there came a tapping, As of some one gently rapping, rapping at my chamber door. "'Tis some visitor," I muttered, "tapping at my chamber door— Only this and nothing more." How does what happens in this stanza propel the action in the poem? It gives the speaker a reason to speak to the raven. It introduces the story and sets up the coming events. It resolves the main conflict of the story. It establishes why Lenore has left the speaker alone.