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: Physiology
[{'content': 'Salivary secretion is by \nSelect and explain. \nA. Na+, Cl reabsorption, B. Na+, K secretion, C. Na+, K+ reabsorption, D. Cl–, HCO3– secretion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Salivary secretion is by Na+, Cl– reabsorption\xa0 and K+, HCO3– secretion.', 'role': 'assistant'}]