In the 1500s, because the spanish had guns, they were able to conquer two great empires—the incas and the aztecs—with only a handful of soldiers. what other reason explains the spaniards’ success? a. the spanish had navigational equipment. b. the incas and aztecs died from european diseases. c. though they had guns, the incas and aztecs were not skilled in modern warfare. d. the incas and aztecs had slower horses.