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: Ophthalmology
[{'content': 'Intraorbital calcification in a patient with proptosis is observed in all except: \nSelect and explain. \nA. Retinoblastoma, B. Orbital varix, C. Hydatid cyst, D. Pseudotumour', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Pseudotumour', 'role': 'assistant'}]