This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Water lilly appearance in a chest radiograph suggests \nSelect and explain. \nA. Metastases, B. Cavitating metastasis, C. Aspergilloma, D. Ruptured hydatid cyst', 'role': 'user'}, {'content': 'Answer: D \nExplanation: .', 'role': 'assistant'}]