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': 'Pneumatocele is seen in fracture of \nSelect and explain. \nA. Maxillary sinus, B. Frontal sinus, C. Ethmoid sinus, D. Sphenoid sinus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pneumatocele is a rare complication following head trauma. The pathophysiology is access of air into the cranium through a fracture involving air sinuses or middle ear roof or depressed fracture of the skull resulting in a craniodental fistula. Frontal bone fracture gives direct access to the cranium.', 'role': 'assistant'}]