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': 'Cotton wool spots in diabetic retinopathy are due to: \nSelect and explain. \nA. Retinal nerve infarcts, B. Retinal holes, C. Retinal haemorrhage, D. Macular degeneration', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Retinal nerve infarcts', 'role': 'assistant'}]