What is a key reason to include allusions in a literary work?

Sister carrie, chapter ii theodore dreiser how does the author prepare readers for the last full paragraph of this passage? a) the author introduces carrie by showing readers the similarities between carrie and her sister, who is married to a hardworking man. b) the author introduces carrie as the jealous sibling of minnie, who works hard to make carrie feel welcome without upsetting her own marital balance. c) the author introduces carrie as an observant and young woman who notices the routine of her sister and brother-in-law, with whom she is staying. d) the author introduces carrie as a rather selfish and naive young woman who accepts the hospitality of her sister and brother-in-law until she can find a job in the city.