You are answering a USMLE-style medical question. Question: A 24-year-old woman is brought to the emergency room (ER) by her co-workers after they found her unconscious in her cubicle when they returned from lunch. They tell you that she has diabetes but do not know anything more about her condition. The woman’s vital signs include: pulse 110/min, respiratory rate 24/min, temperature 36.7°C (98.0°F), and blood pressure 90/60 mm Hg. On physical examination, the patient is breathing heavily and gives irrelevant responses to questions. The skin and mucous membranes appear dry. Examination of the abdomen reveals mild diffuse tenderness to palpation. Deep tendon reflexes in the extremities are 1+ bilaterally. Laboratory studies show: Finger stick glucose 630 mg/dL Arterial blood gas analysis: pH 7.1 PO2 90 mm Hg PCO2 33 mm Hg HCO3 8 mEq/L Serum: Sodium 135 mEq/L Potassium 3.1 mEq/L Chloride 136 mEq/L Blood urea nitrogen 20 mg/dL Serum creatinine 1.2 mg/dL Urine examination shows: Glucose Positive Ketones Positive Leukocytes Negative Nitrite Negative RBCs Negative Casts Negative The patient is immediately started on a bolus of intravenous (IV) 0.9% sodium chloride (NaCl). Which of the following is the next best step in the management of this patient? Options: A) Infuse NaHCO3 slowly B) Switch fluids to 0.45% NaCl C) Start IV insulin infusion D) Replace potassium intravenously Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.