A 9-year-old girl with type 1 diabetes mellitus is brought to the emergency department because of lethargy, labored breathing, and seven episodes of vomiting over the past 6 hours. Her skin is flushed and warm and she appears severely dehydrated. There is a fruity odor to her breath. She is at the 75th percentile for height and 25th percentile for weight. Her temperature is 37.2°C (99°F), pulse is 110/min, respirations are 24/min, and blood pressure is 100/60 mm Hg. Capillary refill time is 4 seconds, and capillary blood glucose concentration is greater than 500 mg/dL. Which of the following is the most appropriate initial step in management? A)Intravenous administration of 20 mL/kg of 5% dextrose in water
B) Intravenous administration of 20 mL/kg of 0.9% saline
C) Intravenous administration of 20 mL/kg of lactated Ringer solution with 40 mEq/L of potassium chloride
D) Intravenous administration of 0.1 U/h of regular insulin
E)Continuous intravenous administration of 0.1 U/h of regular insulin