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: Medicine
[{'content': 'Aerial blood gas analysis of a patient reveals pH 7.2, HCO3 36mmol/L, pCO2 60mm of Hg. The abnormality is : \nSelect and explain. \nA. Respiratory acidosis with compensatory metabolic alkalosis, B. Respiratory acidosis, C. Respiratory alkalosis with compensatory metabolic acidosis, D. Respiratory acidosis with compensatory metabolic acidosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer B (Respiratory acidosis)', 'role': 'assistant'}]