During which period were the people organized as chiefdoms? a) archaic b) mississippian c) paleoindian d) woodland

The answer is b.  Missisippian. During this time, culture started in the Mississippi where agriculture that came from corn started to spread.  This helped sustain big populations due to large outputs of agricultural harvests. It was here were chiefdoms began as people swore their loyalty to the most significant group.  Social classes were created as a result with the nobility at the top.