<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 62-year-old man presents to the emergency room with an acute myocardial infarction. Twenty-four hours after admission to the cardiac intensive care unit, he develops oliguria. Laboratory tests show that his serum BUN is 59 mgdL and his serum creatinine is 6.2 mgdL. Renal biopsy reveals necrosis of the proximal tubules and thick ascending limb of Henles loop. Which of the following would you most likely observe on a microscopic examination of this patients urine?? A: White blood cell casts, B: Fatty casts, C: Muddy brown casts, D: Hyaline casts, E: Broad waxy casts,  <response>: This is a question about acute kidney injury in the setting of an acute myocardial infarction. The patient has developed oliguria and has elevated BUN and creatinine indicating acute kidney injury. The biopsy findings of proximal tubule and thick ascending limb necrosis indicate acute tubular necrosis. In acute tubular necrosis, the tubular epithelial cells are damaged and slough off into the tubular lumen. This results in the formation of casts composed of Tamm-Horsfall protein and cellular debris. These casts have a muddy brown appearance and are known as muddy brown casts.So the correct answer here is option C, as we would expect to see muddy brown casts in the urine in this case of acute tubular necrosis.C: Muddy brown casts 