The descendants of american indians originally migrated from
a.
asia
b.
europe
c.
africa
d.
mexico

A.  Asia, like Mongolia, Koreans ad the japans.

Explanation:

The scientific evidence links the indigenous people of the America to the Asian people especially the Siberian and the Koryak people. And have been linked to the north Asian population by the blood type and the genetic compositions and they moved to Americas from somewhere east of the Yenisei River. DNA holographs of A, B, C, D have been recognized by the eastern Asian and those of the indigenous population.

The descendants of American Indians originally migrated from Asia. The correct option among all the options that are given in the question is the first option or option "A". a small group of migrants from Asia is thought to have migrated to the united states during the time of ice age. I hope it helps you. 

Answerwill have thinner; have thicker oceanic sediments;

Answer carbon dioxide ice;