This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'Defect most commonly occuring in congenital rubella is - \nSelect and explain. \nA. Cataract, B. Deafness, C. Microcephaly, D. Blindness', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A cataract is the most common defect in congenital rubella REF:ANATHANARAYANAN MICROBIOLOGY NINTH EDITION PAGE.555', 'role': 'assistant'}]