Why does the author mention Oates' book Them?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each ofthe questionsfrom 36 to 42.
Joyce Carol Oates published her first collection of short stories, By The North Gate, in 1963, two years after she had received her master's degree from the University of Wisconsin and become an instructor of English at the University of Detroit. Her productivity since then has been prodigious, accumulating in less than two decades to nearly thirty titles, including novels, collections of short stories and verse, play and literary criticism. In the meantime, she has continued to teach, moving in 1967 from the University of Detroit to the University of Windsor, in Ontario, and, in 1978, to Princeton University Reviewers have admired her enormous energy, but find a productivity of such magnitude difficult to assess.
In a period characterized by the abandonment of so much of the realistic tradition by authors such as John Barth, Donald Barthelme, and Thomas Pynchon, Joyce Carol Oates has seemed at times determinedly old-fashioned in her insistence on the essentially mimetic quality other fiction. Hers is a world of violence, insanity, Fractured love, and hopeless loneliness. Although some of it appears to come from her own direct observations, her dreams, and her fears, much more is clearly from the experiences of others. Her first novel With Shuddering Fall (1964), dealt with stock car racing, though she had never seen a race. In Them (1969) she focused on Detroit from the Depression through the riots of 1967, drawing much of her material from the deep impression made on her by the problems of one of her students. Whatever the source and however shocking the events or the motivations, however, her fictive world remains strikingly akin to that real one reflected in the daily newspapers, the television news and talk shows, and popular magazines of our day.