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': 'Most common cause of U/L mucopurulent rhinorrhea in a child is: \nSelect and explain. \nA. Foreign body, B. Adenoids which are blocking the airways, C. Deted nasal septum, D. Inadequately treated acute frontal sinusitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A unilateral nasal discharge is nearly always due to foreign body and if duscharge has an unpleasant smell,it is pathognic. If a child presents with unilateral,foul smeling nasal discharge,foreign body must be excluded. Ref Dhingra 6/e,p 161.', 'role': 'assistant'}]