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': 'Bicarbonate is maximally absorbed from: \nSelect and explain. \nA. PCT, B. DCT, C. Collecting duct, D. Thick ascending loop of Henle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. PCT', 'role': 'assistant'}]