Read the following paragraph and answer the question. 1 poe really was the inventor of the detective story, which he called the "ratiocinative" tale. 2 here believing the effect intended was "to perplex the reader and whet his desire for elucidation," he originated two devices useful to this day. 3 one might be called "the device of the baffled friend": he gave his brilliant detective a companion not good at solutions and had him tell the story. 4 viewing the happenings through this narrator's eyes, the reader shares his growing puzzlement. 5 poe used his second device at the tale's end: he had the detective disclose his surprising solution and then "elucidate" step by step the reasoning which led to it. 6 "the purloined letter" demonstrated poe's use of these two devices in a detective story. the main sentence of the paragraph is sentence number?