This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid and electrolytes, Subject name: Medicine
[{'content': 'The finding of urine sodium concentration <20 mmol/L in hypovolemic hyponatremia implies \nSelect and explain. \nA. Salt-wasting nephropathy, B. Diuretic therapy, C. Hypoaldosteronism, D. Trauma', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Hypovolemic hyponatremia Urine sodium concentration >20 mmol/L Renal losses Diuretic excess Mineral coicoid deficiency Salt-losing deficiency Bicarbonaturia with Renal tubal acidosis and Metabolic alkalosis Ketonuria Osmotic diuresis Cerebral salt wasting syndrome Urine sodium concentration <20 mmol/L Extrarenal losses Vomiting Diarrhea Third spacing of fluids Burns Pancreatitis Trauma Ref: Harrison 19e pg: 299', 'role': 'assistant'}]