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
Calcification in retinoblastoma is due to 
Select and explain. 
A. Necrosis, B. Hemorrhage, C. Scleral rupture, D. RPE metaplasia
D: RPE metaplasia
Answer: D: RPE metaplasia 
Explanation: Calcification in retinoblastoma is due to retinal pigment epithelium metaplasia.