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
Commonest eye tumour is: 
Select and explain. 
A. Melanoma, B. Retinoblastoma, C. Carcinoma of eyelid, D. Carcinoma of lacrimal sac
B: Retinoblastoma
Answer: B: Retinoblastoma 
Explanation: Ans. Retinoblastoma