Pa is ashamed of himself because he’s irritated by the fact that Noah is quiet and slow, in contrast to Ma, who has unconditional love for al members of her family.
From the answers given.
I would go with D, as Non-fiction isn't locked to politics or science; It's moreover use to categorize literature (books, etc...) that are based solely on fact.
I tried to search for the info about the literature but it was too general. I guess it is not what your instructor requires. That is why I recommend you to check what the writers can suggest you. Go to Prime Writings site and let them analyze your work in a professional way.