question: Q:A 53-year-old woman presents to her physician for evaluation of sudden onset respiratory distress for the past few hours. The past medical history includes a myocardial infarction 2 years ago. The vital signs include a blood pressure 70/40 mm Hg, pulse 92/min, respiratory rate 28/min, and SpO2 92% on room air. The physical examination reveals bilateral basal crepitations on auscultation. The echocardiogram reveals an ejection fraction of 34%. She is admitted to the medical floor and started on furosemide. The urine output in 24 hours is 400 mL. The blood urea nitrogen is 45 mg/dL and the serum creatinine is 1.85 mg/dL. The fractional excretion of sodium is 0.89 %. Urinalysis revealed muddy brown granular casts. Which of the following is the most likely cause of the abnormal urinalysis?? 
  {'A': 'Acute glomerulonephritis', 'B': 'Chronic kidney disease', 'C': 'Acute pyelonephritis', 'D': 'Acute interstitial nephritis', 'E': 'Acute tubular necrosis'},