21.A 28 y/o young male visited your outpatient clinic with an elevated blood pressure of 148/100 mmHg. He denies taking any medications, but has a family history of hypertension. His laboratory values were: [Na] 140 mEq/L, [K] 3.1 mEq/L, [Cl] 98 mEq/L, BUN 25 mg/dL, Creatinine 0.9 mg/dL, Glucose: 85 mg/dL. The arterial blood gas (ABG) test reveals: Arterial pH: 7.48, PCO2: 46 mm Hg, HCO3-: 34 mEq/L. What is the most appropriate characterization of his acid-base disorder?
(A)Metabolic alkalosis
(B)Metabolic alkalosis and respiratory acidosis
(C)Respiratory alkalosis and metabolic acidosis
(D)Metabolic alkalosis and respiratory alkalosis
(E)Respiratory alkalosis