It's saying that Atticus is a respectable person who doesn't see race as a reason to or to not defend someone; he's not racist. It shows that racism in the south is common, and that because of that, Scout has grown up being taught to be racist. Atticus is trying to turn her away from that and get her to focus on the person's true self, not the color of their skin.
Your answers are Science and People. "The effect of pollution on fish" is the only answer choice that is not too vague to write about or to discuss. Hope this helped!
