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': "A 60 year man had undergone cardiac bypass surgery 2 days back. Now he started forgetting things and was not able to recall names and phone numbers of his relatives. What is the probable diagnosis : \nSelect and explain. \nA. Depression, B. Post traumatic psychosis, C. Cognitive dysfunction, D. Alzheimer's disease", 'role': 'user'}, {'content': 'Answer: C \nExplanation: The tendency to forget and inability to remember events immediately after cardiac bypass surgery suggests a diagnosis of cognitive dysfunction. Cognitive dysfunction present with impaired memory & intellect. Major surgery like prolonged cardiopulmonary bypass is one of the most consistent risk factors for cognitive dysfunction.', 'role': 'assistant'}]