1) The Aztec society found by the Spanish in their arrival was characterized by a centralized State whose power was based on the force of their military. The Aztecs were an empire full of highly complex cities (A).
Historically it is not correct to talk about a long Aztec empire in the region. "Aztecs" of the time of the Spanish arrival really called themselves Mexicas. The term “Aztecs” is how this civilization – composed of various peoples – started to be called in the XIXth century by European authors.
In the 1400s the Mexicas conquered the city-states around them and built a tax empire. They controlled these cities through their military, charging taxes and supporting friendly leaders.
It was this variety of peoples under this empire that made it vulnerable to the Spanish, who knew how to use these conflicts against the Mexicas.
2) The Maya civilization was at its height between 250 and 900 CE. It was composed of various city-states which were not unified despite cultural similarities (D). They were much more a complex of big cities than an empire.
The Maya society had its hierarchies: they had a ruler whose title was the Hunac Ceel and it was seen by the people to represent their gods. Nobles and clergymen were right below him. The base of the society was the artisans and free workers, mostly agriculturists.