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: Pharmacology
Which of the following metabolic abnormality is seen with long term use of spironolactone? 
Select and explain. 
A. Metabolic acidosis, B. Metabolic alkalosis, C. Hyperkalemia, D. None of the above
A: Metabolic acidosis
Answer: A: Metabolic acidosis 
Explanation: By inhibiting H+ secretion in parallel with K+ secretion, the K+-sparing diuretics can cause acidosis similar to that seen with type IV renal tubular acidosis. Ref: Katzung, 11th edition, Chapter 15.