Answer:
C. It united all the people under a central government.
Explanation:
One intriguing feature about a city-state is that it is independent and sovereign. It has complete control over its own territory and has a strong central government that unites all the citizens under one sovereign authority.
City-states have thier own identities and people living there can exercise numerous rights and enjoy several freedoms. A popular example of a city-state was the city of Athens. It was one the earliest city-states in the world.