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: Medicine
[{'content': "Which of the following is the most common cause of hypergonadotrophic hypogonadism in males- \nSelect and explain. \nA. Viral orchitis, B. Klinefelter's syndrome, C. Kallman's syndrome, D. Noonan syndrome", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]