This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidneys and Body Fluids, Subject name: Physiology
[{'content': 'Collection duct has which cells \nSelect and explain. \nA. Principal and intercalated, B. Parietal and oxyntic cells, C. Lacis cells, D. Podocytes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Principal and intercalated(Ref: Ganong, 25th ed/p.672)Colleting duct is made up of two types of cell: principal cells (P cells) and intercalated cells (I cells)', 'role': 'assistant'}]