This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Myxo Viruses, Subject name: Microbiology
[{'content': 'Most common cause of bronchiolitis in children? \nSelect and explain. \nA. RSV, B. Papova virus, C. Adenovirus, D. H3N1', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) RSV', 'role': 'assistant'}]