Nationalism began to grow and spread. (which is the last one)
A, I checked on usa test prep
Maya observed the sky and calendars to predict solar and lunar eclipses, the cycles of the planet Venus, and the movements of the constellations.
In Aztec social hierarchy, people who are called "Serfs" are the ones expected to support the upper class. They belong to the lowest social class in the Aztec culture and required to do labors for the nobles. As for the Incas, "Commoners" (farmers, artisans, servants, etc.) are required to support the higher class for they do not practice slavery. Majority of Inca's population belongs to the commoner class.