As the chiefdoms ended, what became of different american indian groups?
they formed new cultural groups.
they abandoned their groups entirely.
they resettled in europe.
they adopted european identities.

I believe it is They formed new cultural groups.

Explanation:

After the chiefdom ended it said they formed new cultural groups it should be that!

i believe

clean air is essential for health and survival

clean air provides nitrogen gas for plant respiration

clean air supplies oxygen that enables living organisms to breathe

hope this

i am brianly

sorry if this doesn't