The response that best reflects the extent and operation of the Inca Empire is: "The Inca Empire extended across the Andes Mountains along the western side of South America."
This statement accurately describes the geographical reach of the Inca Empire, which primarily occupied the Andes region and did not extend significantly to the Atlantic Ocean or the Amazon River basin. Additionally, while the Inca road system was extensive, it did connect different parts of the empire, including north to south, rather than only traveling east to west.