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: Unknown
[{'content': 'The following condition is not associated with an increased anion-gap type of metabolic acidosis \nSelect and explain. \nA. Shock, B. Ingestion of ante-freeze, C. Diabetic ketoacidosis, D. COPD', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ref: Harrison’s 18/e p369, 17/e p292\n\xa0\nIn COPD blood pH is usually maintained within normal range in spite of increased PaCO2 because of renal compensation which leads to retention of bicarbonates', 'role': 'assistant'}]