On the other are people who believe that Americans are getting fatter because of powerful environmental factors like cheap corn, fast food, and ________advertising.
句意：另一派的人们相信，美国人变胖应归咎于强大的环境因素，像便宜的玉米、快餐食品和肆无忌惮的广告。unscrupulous肆无忌惮的；寡廉鲜耻的。scrupulous细心的；小心谨慎的。moral道德的；精神上的。surplus剩余的；过剩的。因此，本题的正确答案是B。