This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Which of the following values are suggestive of acute tubular necrosis : \nSelect and explain. \nA. Urine osmolality>500, B. Urine sodium>40, C. Blood urea nitrogen/plasma creatinine>20, D. Urine creatinine /plasma creatinine>40', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (Urine sodium > 40) Urinary sodium excretion of more than 20mmol/L suggests intrinsic renal failure such as ATN Urine Diagnostic Indices: Differentiation of Prerenal and Intrinsic Renal failure. Acute tubular necrosis is a cause of Intrinsic ARF.Q', 'role': 'assistant'}]