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: Orthopaedics
[{'content': 'True about osteochondromatosis - \nSelect and explain. \nA. Malignant, B. Manifest at adult, C. Knee is the most common size, D. Common in women', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most of the guides have wrongly explained this question because they have explained synovial chondromatosis in this, question.\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0 •\nFirst, let me tell you that osteochondromatosis and synovial chondromatosis (synovial- osteochondromatosis) are different diseases.\nOsteochondromatosis is the presence of multiple osteochondroma in the body, e.g. in multiple hereditary exostosis.\nOsteochondroma is a benign tumour and occurs in teenager and young adults.\nSo, the answer to this question is b, i.e. manifest at adult.\nIf the question would have been synovial osteochondromatosis then the answer is b & c.', 'role': 'assistant'}]