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': "Which of the following is most common metastatic tumour of orbit: March 2013 \nSelect and explain. \nA. Hodgkin's lymphoma, B. Chloroma, C. Malignant nasopharyngeal tumours, D. Breast carcinoma", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C i.e. Malignant nasopharyngeal tumours', 'role': 'assistant'}]