Answer:
The main sentence of the paragraph is sentence number 1
Step-by-step explanation:
The main sentence has to present the general idea of the complete piece of work, sentence number 1 "Poe really was the inventor of the detective story, which he called the "ratiocinative" tale" presents the general idea that is the creation of the ratiocinative tale, later the other sentences give examples and expand the definition of this invention.