This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
[{'content': 'Most common primary intraocular tumor in children \nSelect and explain. \nA. Retinoblastoma, B. Malignant melanoma of choroid, C. Malignant melanoma of ciliary body, D. Rhabdomyosarcoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) RetinoblastomaRef: Kanski 7/e, p. 510Retinoblastoma - most common intraocular tumor in children.Rhabdomyosarcoma - most common orbital malignant tumor in children.', 'role': 'assistant'}]