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': 'Harish 45 years old male admitted in hospital, says that nurse who is treating him is not actually nurse, his wife has replaced her and trying to killed him. Diagnosis. \nSelect and explain. \nA. Capgrass syndrome, B. Fregoli syndrome, C. Cotard syndrome, D. Alport syndrome', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Fregoli syndrome : Patient believes that family member has come in disguise of stranger.', 'role': 'assistant'}]