Author and journalist Eric Schlosser's book Fast Food Nation examines the fast food industry in the United States. In the ninth chapter of the book, the author visits a slaughter house, describes the occupational hazards of employees in meat industry. He also mentions the case of infested meat and how it creates health risk for people's lives. The point the writer makes shows that the correct answer is B.
I believe the answer is A. In Gumption, the dialogue helps develop the characters, while in The Secret Life of Walter Mitty, the dialogue helps distinguish real life from Walter Mitty's imagination.