How does a timeline identify dates before the common era ?

i think is "Common Era" is used to mark time in the same way. B.C. means "before Christ" and B.C.E. stands for "Before the Common Era"

Explanation:

the answer is b: the religion they practice.

here's why:

there were many different native american tribes and those with similar characteristics formed a main tribe or nation. each had its own language, religion and customs.