This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
[{'content': 'At what atmosphere pressure gradient barotraumatic otitis media occurs \nSelect and explain. \nA. 80 mm of Hg, B. 90 mm of Hg, C. 100 mm of Hg, D. 120 mm of Hg', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]