This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
[{'content': 'Maximum reabsorption of HCO3 - occurs in \nSelect and explain. \nA. PCT, B. DCT, C. CD, D. Loop of henle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The process of bicarbonate reabsorption occurs predominantly in the proximal tubule (about 90%). The rest occur in the thick ascending limb and in the collecting tubule. All involve hydrogen ion secretionRef: Ganong&;s Review of Medical Physiology, 23rd edition, page no: 680', 'role': 'assistant'}]