This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory Failure, Subject name: Medicine
[{'content': 'In type II respiratory failure there is: \nSelect and explain. \nA. Low pO2 and Low pCO2, B. Low pO2 and High pCO2, C. Normal pO2 and High pCO2, D. Low pO2 and Normal pCO2', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Type I respiratory failure Type II respiratory failure Low pO2 Low pO2 Normal or low pCO2 High pCO2 A-a gradient is increased A-a gradient is normal because Hypoventilation leads to reduction of both pAO2 and paO2', 'role': 'assistant'}]