A 21-Year-Old Man with Insulin-Dependent (Type 1)diabetes Mellitus Who Forgot

A 21-year-old man with insulin-dependent (type 1) diabetes mellitus who forgot to inject his insulin is seen in the emergency department.The following laboratory data are obtained: Serum [Na⁺] = 140 mEq/L (normal: 135 to 147 mEq/L)
Serum [K⁺] = 6.5 mEq/L (normal: 3.5 to 5.0 mEq/L)
Serum [HCO₃^-] = 10 mEq/L (normal: 22 to 28 mEq/L)
Blood pH = 7.0 (normal: 7.35 to 7.45)
Arterial partial pressure of carbon dioxide (Pco₂) = 25 mm Hg (normal: 33 to 44 mm Hg)
Serum glucose concentration = 1000 mg/dL (normal: 70 to 110 mg/dL)
Which of the following plays the most important role in the generation of hyperkalemia in this man?

A) Low plasma osmolality
B) Low arterial Pco₂
C) Hyponatremia
D) Metabolic acidosis
E) Low plasma insulin concentration