Choice D is the best answer. In lines 74-79("noticeable...button"), the narrator describes Mr. Peters as "gray" and balding, noting that he has "lost weight" and his color is "poor." This description suggests Mr. Peters is aging and losing strength and vigor.
Choices A, B, and C are incorrect because the description of Mr. Peters in lines 74-79 ("noticeable... button") suggests he is a person who is wan and losing vitality, not someone who is healthy and in good shape (choice A), angry and intimidating (choice B), or emotionally anxious (choice C).