Ans. is 'd' i.e., Rhabdomyolysis Approach to red to brown urineo The excretion of red to brown urine is observed in a variety of clinical settings. The initial step in the evaluation of this abnormality is centrifugation of the urine to see whether the red color is in the urine sediment or the supernatanto If the red color is seen only in the sediment (and the supernatant is not red), the patient has hematuriao If, on the other hand, the supernatant is red, then the supernatant should be tested for heme with a urine dipstick:# If a urine dipstick of the red supernatant is positive for heme, the patient has either hemoglobinuria or myoglobinuria.# If a urine dipstick of the red supernatant is negative for heme, the patient may have one of a variety of unusual conditions.