The correct answer is C) the highest class of social rank.
As city-states increased in size, control of record, taxes, and the military was the role of the highest class of social rank.
During the early civilizations, as city-states increased in size, the highest class of social rank had the most important privileges such as the control of the record, taxes, and the military. These high-class rulers emerged as the leaders and governors of many territories that were continually expanding to gain power and dominion over those regions. They used religious beliefs and different level of education to keep the hierarchy system operating.