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
The following condition is not associated with an increased anion-gap type of metabolic acidosis 
Select and explain. 
A. Shock, B. Ingestion of ante-freeze, C. Diabetic ketoacidosis, D. COPD
D: COPD
Answer: D: COPD 
Explanation: Ref: Harrison’s 18/e p369, 17/e p292
 
In COPD blood pH is usually maintained within normal range in spite of increased PaCO2 because of renal compensation which leads to retention of bicarbonates