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': 'Dilution segment in nephron is: \nSelect and explain. \nA. Ascending LOH, B. Descending LOH, C. Collecting tubule, D. Proximal tubule', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. a. Ascending LOH', 'role': 'assistant'}]