This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
[{'content': 'Post traumatic stress syndrome is due to : \nSelect and explain. \nA. Head injury, B. CVD, C. Minor stress, D. Major life threatening events', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Post - traumatic stress disorder occurs after on extreme traumatic events involving the threat of personal death or injury.', 'role': 'assistant'}]