It sparked a domino effect of other nations making those nations rebel as well.
The answer is (B) because they believed that slavery would be a local option called popular sovereignty.
Any options? A reason US joined the war was because German subs destroyed lusitania which had Americans on it. That's one of the main reasons we joined the war, if that's a option for your question then that's it.
If that is not a option let me know and i can further assist
The best answer to the question is B
