This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'All except one is required for the diagnosis of obesity hypoventilation syndrome \nSelect and explain. \nA. Hypeension, B. Sleep disorder breathing, C. BMI more than or equal to 30 kg/m2, D. PaCO2 more than or eqal to 45 mmHg', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Repeated', 'role': 'assistant'}]