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': 'Arterial blood gas analysis of a patient admitted to the medical emergency is as follows : pH = 7.2, HCO3 = 38 mmol/L, pCO2 = 56 mm Hg. This indicates : \nSelect and explain. \nA. Metabolic acidosis, B. Metabolic acidosis with respiratory compensation, C. Respiratory acidosis, D. Respiratory acidosis with renal compensation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]