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': 'All of the following are seen in rockets, except - \nSelect and explain. \nA. Bow legs, B. Gunstock deformity, C. Pot belly, D. Cratio tabes', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]