Please select the word from the list that best fits the definition

A division of society by rank or class
here is the list

polytheism
epics
silt
chariot
surplus
architecture
empire
priests
cuneiform
fertile crescent
pictographs
scribe
alphabet
rural
urban
irrigation
ziggurat
impact
monarch
role
canals
division of labor
social hierarchy
city-state

...long list right i know i had to type all of this :|