“immediate reasons for pizarro’s success included military technology based on guns, steel weapons, and horses… [and the] centralized political organization of european states” (diamond 80) diamond, jared. guns, germs, and steel: the fates of human societies. new york: norton, 1997. print. 7. the author’s claim is structured upon: (a) marxist historiography. (b) geographic & environmental advantage. (c) oral history. (d) biography.