This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'The incidence of the mucocele is lowest in \nSelect and explain. \nA. Frontal sinus, B. Sphenoid sinus, C. Maxillary sinus, D. Ethmoid sinus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Paranasal sinus mucoceles most commonly occur in the third or fouh decades of life with a slight male predilection. The frontal sinus is most commonly affected followed by the ethmoid sinuses, with repos suggesting 70-90 % of mucoceles occur in these locations.Ten percent of mucoceles occur in the maxillary sinus and the sphenoid sinus is involved rarely.', 'role': 'assistant'}]