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: Radiology
[{'content': 'Well defined rounded opacity is the lung with cause irregular calcification is a feature of: \nSelect and explain. \nA. Hamaoma, B. Hydatid cyst, C. Amoebic abscess, D. Ca lung', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Hamaoma', 'role': 'assistant'}]