For history why might most of the major pre-columbian mesoamerican civilizations have existed in the areas of southern mexico?

Southern Mexico provided more resources than other parts of Mexico, another reason is humans didn't realize they could transport goods and resources to other places. It was normal at this time for people to gather where there is high amounts of resources.

Hope this helps! Brainliest answer plz :)

C. congress was able to pay debts run up in the war