Answer:
Correct answer is Each city-state was independent and had its own form of government.
Step-by-step explanation:
City-states were totally independent political entities, that had their own political systems, government... Sometimes they would made alliances with other city-states, but that wouldn't harm their autonomy. The best example for this are Greek or Sumerian city states.
All other options are not correct as they are not reflecting what the city states really were.