You are doing an inter-facility transfer from a small rural hospital to a regional trauma center. The patient was the victim of an industrial accident and has crush injury syndrome. Upon moving the patient to your stretcher, you notice that the patient's Foley catheter contains tea-colored urine. The patient is awake and alert complaining of severe pain. Breath sounds are clear and equal. His vitals are: pulse 104, respirations 20, and BP 112/60. His right lower extremity is immobilized, and he does have pulses and sensation in his right foot. Which part of your assessment indicates that the patient may have increased levels of myoglobin?

a) Clear and equal breath sounds
b) Severely immobilized right lower extremity
c) Tea-colored urine in the Foley catheter
d) Pulses and sensation in the right foot