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': 'All of the following take pa in the pathogenesis of macular edema in diabetic retinopathy except: \nSelect and explain. \nA. Retinal pigment epithelium dysfunction, B. Oxidative stress, C. VEGF, D. Increased protein kinase-C', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Retinal pigment epithelium dysfunction', 'role': 'assistant'}]