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': 'TF/P ratio for PCT for many substances are shown in diagram below. Which of them represents urea? \nSelect and explain. \nA. 1, B. 2, C. 3, D. 4', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. 2Line 1: Not reabsorbed or actively secreted in PCT e.g. PAH, Creatinine, Inulin.Line 2: Freely filtered and poorly reabsorbed like UreaLine 3: no change in concentration along PCTLine 4: Bicarbonate: 90% is reabsorbed in PCT decreasing its tubular fluid concentration Line5: Solute fully reabsorbed in PCT like glucose.', 'role': 'assistant'}]