D.)increased migration of people for economic opportunity
I believe that one main reason why is 1. Woodrow Wilson (Who was a democrat) he believed that he did not need to bring anyone from the Senate, which was a Republican :) (I hope this helps! I read this from the internet, I was gonna post it to you but I dont know if its against the rules of Brainly :) If not let me know, and ill send the link)
The final commander was Ulysses S. Grant
i think the answer is the third one
