Answer:
C. Chiefdoms.
Step-by-step explanation:
Serfdom is not a political unit, but a term describing a farmer in the middle ages in Europe who worked another lord´s land and did not own his own property. Kingdoms are also generally European, and the natives were definitely not ruled by a king. States are individual parts of a country, as in the United STATES of America. Chiefdoms are the only answer even remotely associated with the Native American peoples.