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: Surgery
[{'content': 'Soap bubble appearance on Xray is seen in which bone tumor ? \nSelect and explain. \nA. Osteogenic sarcoma, B. Giant cell tumor, C. Multiple myeloma, D. Chondroblastoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'A' i.e., Rheumatoid ahritis Repeat from previous sessions. See explanation-3 of session-3.", 'role': 'assistant'}]