Paragraph Function. Paragraphs are used to help your reader follow the logic of your argument. They should not be too long (generally speaking, paragraphs that are longer than 3/4 of a page are probably too long) or too short (one or two sentence paragraphs probably haven't given your reader enough information).
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.
