Read the excerpt below and answer the question. It hadn’t ever come home to me before, what this thing was that I was doing. But now it did; and it stayed with me, and scorched me more and more. I tried to make out to myself that I warn’t to blame, because I didn't run Jim off from his rightful owner; but it warn’t no use, conscience up and says, every time, “But you knowed he was running for his freedom, and you could a paddled ashore and told somebody.” That was so—I couldn't get around that noway. That was where it pinched. Conscience says to me, “What had poor Miss Watson done to you that you could see her n*gger go off right under your eyes and never say one single word? What did that poor old woman do to you that you could treat her so mean? Why, she tried to learn you your book, she tried to learn you your manners, she tried to be good to you every way she knowed how. THAT’S what she done.”

Which is most likely the reason why Twain included this excerpt to discuss social norms?

to show the importance of obeying social norms
to show how violating social norms can conflict someone
to show that social norms can be violated if they are not morally right
to show that social norms are entirely relative