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': 'The most commonly seen primary orbital tumour in children is: \nSelect and explain. \nA. Rhabdomyosarcoma, B. Glioma of optic nerve, C. Optic nerve sheath meningioma, D. Retinoblastoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Rhabdomyosarcoma', 'role': 'assistant'}]