This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
[{'content': 'In normal kidneys, which of the following is true of the osmolarity of renal tubular fluid that flows through the early distal tubule in the region of the macula densa?(2018) \nSelect and explain. \nA. Usually isotonic compared with plasma, B. Usually hypeonic compared with plasma, C. hypeonic compared with plasma in antidiuresis, D. Usually hypotonic compared with plasma', 'role': 'user'}, {'content': 'Answer: D \nExplanation: distal tubule, paicularly its first pa, is in an extension of the thick segment of the ascending limb. It is relatively impermeable to water, and continued removal of the solute in excess of solvent fuher dilutes the tubular fluid(hypotonic fluid). Ref:- Ganong, pg num:-684', 'role': 'assistant'}]