Paleolithic era that lasted from earliest humans to about 10,000 years ago. a
Jurassic Age
b
Ice Age
c
Old Stone Age
d
New Stone Age

C. old stone age

Explanation:

the historians cited in the article all agree with one another about the cause of the civil war. despite coming from different backgrounds and cultures, the historians agree that slavery was the root cause of the civil war. the fact that all these historiansgenerally agree with one another makes their shared viewpoints more reliable and valid, especially because the historians have different backgrounds and all work for the well-respected institutions of howard university, clemson university, and the university of colorado.

i truly dont know the answer wait i do its 1,3,4