I'm pretty sure (1.) is A, and I know for a fact that (3.) is D because slavery was a regular practice between quarreling tribes. I have no clue what (2.) is. Best of luck.
Answer:
i think the best answer is C.
Answer:
to amend the Articles of Confederation
It would be "industrialization," that was a significant factor in both the german wars for unification and United States' Civil War, since Industrialization led to an irreconcilable economic split between two more major segments of each area.