Boo Radley was a good person but perceived as someone who must be isolated. He himself chose to isolate himself from society. The justice about whether to judge him as a murderer or a defender was overlooked by Atticus because of Raley's history. The instability of Boo's family highlights the theme of how even within homes, equal human rights can be ignored. Aunt Alexandra is traditional and prejudice at first but becomes open to the views of Atticus because of her love for the family.
D. A dependent clause is one in which it could not be its own sentence without causing a fragmental sentence. Think about it like this, if someone walked up to you and said all of those to you, because they went to school requires more information.