This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Physiology
[{'content': 'In the stomach, H+ ions are secreted in exchgHjjii for \nSelect and explain. \nA. Na+, B. K+, C. Gar, D. CT', 'role': 'user'}, {'content': 'Answer: B \nExplanation: H+ ions are generated inside parietal cells from metabolic CO2 & H2O present in cell in the presence of enzyme carbonic anhydrase. -The enzyme accelerates the formation of H2CO3 which dissociates to release H+ & HCO3-. -The H+ ions generated are then secreted into the lumen of the canaliculi in exchange for K+ by a primary active transpo mediated by a H+-K+-AT Pase pump. Ref: Medical Physiology, Indu Khurana', 'role': 'assistant'}]