This question is not about the diagnostic features of PTSD. This is about the differential diagnosis. PTSD is an anxiety disorder and it shares symptoms with other disorders. Impoant features in distinguishing the condition are given below. Differential diagnosis: Point 1: Etiologically significant trauma should be present for a diagnosis of PTSD. E.g. A traumatic event in the past. Point 2: 'Intentionality' or 'aboutness' is an impoant factor for PTSD. Nightmares, flashbacks or reliving experiences should be related to the past event. PTSD concerns memory - Intrusion of past stressors into the present. Point 3: Avoid a 'stimulus' or 'activity' that provokes the memory of the past event. In the above question, only reliving experience is mentioned as connected to the past experiences. Hence, that is the answer for this question. All other symptoms can be see in other anxiety disorders. Ref: Kaplan & Sadock's, Comprehensive Textbook of Psychiatry, 9th Edition, Page 2659