This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Pharmacology
[{'content': 'Acetazolamide acts at \nSelect and explain. \nA. PCT, B. DCT, C. Ascending loop of Henle, D. Descending loop of Henle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Acetazolamide is a reversible inhibitor of the carbonic anhydrase enzyme that results in the reduction of hydrogen ion secretion at the renal tubule and increased renal excretion of sodium, potassium, bicarbonate, and water by inhibiting the enzyme CA', 'role': 'assistant'}]