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: Microbiology
[{'content': 'Most common defect of congenital rubella syndrome \nSelect and explain. \nA. salt and pepper retinopathy, B. Cataract, C. Sensorineural deafness, D. PDA', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]