A Patient Has Acute Tubular Necrosis

A patient has acute tubular necrosis.The following blood work was noted: complete blood count shows a white blood cell count of 11,000 mm³,a hemoglobin of 8 g/dL,and a hematocrit of 30%.His chemistry panel shows serum potassium,4.5 mg/dL; serum sodium,135 mg/dL; serum calcium,8.5 mg/dL; BUN,20 mg/dL; and creatinine,1.5 mg/dL.What laboratory value(s) need(s) to be treated most immediately and why?

A) Administration of 5% dextrose in water and insulin because the patient is hyperkalemic and needs this level reduced
B) Administration of Epogen to treat anemia
C) Administration of a broad-spectrum antibiotic to treat the elevated blood cell count
D) Administration of a calcium supplement for low calcium