The correct answer should be D.Confederate troops were outnumbered, but they usually won
They weren't difficult losses however. The Union would have to fall back but it wasn't a terrible loss. The battles with high kill counts started coming later in the war.
I think the correct answer from the choices listed above is option C. The ruling in Plessy v. Ferguson may have affected the legalities of segregation by redefining the concepts of "separate but equal". The segregation became a law in the United States. After this, Jim Crow laws were implemented that is meant to discriminate the African Americans.