Refer to the map. Map of the Inca Road System in South America in the 1400's. A key notes the shaded region as the Inca Empire. Lines represent Inca roads. Major Inca cities are labeled with large dots.

Which of the following best describes a common effect of the Inca road system and the Silk Road on their respective regions?

Both enabled a single empire to conquer the peoples along the route.
Both unified the peoples along the route under a central government.
Both brought about intercultural exchange among the peoples along the route.
Both made products from other continents available to the peoples along the route.