3. What evidence is there that overland trade from Mexico City might have been difficult?

Mountains in Mexico

Explanation:

Mexico has several mountains owing to it having two very prominent mountain ranges known as the Sierra Madre Occidental and the Sierra Madre Oriental. These mountains were big hindrances to travel across Mexico.

Mexico City sits on the confluence of these two great ranges which means that any trade overland to and from Mexico City would have to go over mountains and this shows that trade might have been difficult.