This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
[{'content': 'M/c causes of epistaxis in 3years old child: \nSelect and explain. \nA. Nasal polyp, B. Foreign body, C. Upper respiratory catarrh, D. Atrophic rhinitis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: M/C cause of epistaxis in children is idiopathic 2nd most common of epistaxix in children is: infection/trauma-development of crusts-nasal picking/digital trauma-nasal bleed. Ref.Scott Brown 7/e,vol 1,p 1064.', 'role': 'assistant'}]