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': 'Most common cause of rubeosis iridis \nSelect and explain. \nA. Tumor, B. CRAO, C. Radiation retinopathy, D. Diabetic retinopathy', 'role': 'user'}, {'content': "Answer: D \nExplanation: it develops following retinal ischemia which is a common feature of:\n●proliferative diabetic retinopathy \n●central retinal vein occlusion \n●sickle cell retinopathy \n●Eale's disease", 'role': 'assistant'}]