Choice A (IV 1,000mL of 0.9% NaCl) is an isotonic crystalloid fluid helpful in a patient with depleted intravascular volume (i.e., dehydration). This patient is clinically dehydrated (dry oral mucosa and mild tachycardia); however, hypertonic 3% NaCl is a more appropriate initial treatment. Choice B (IV 50mL of 25g dextrose solution, or commonly known as “D50”) is an appropriate treatment for a patient with hypoglycemia. Checking a glucose level is a crucial part of the initial assessment of all patients with altered mental status, but this patient has a reported normal glucose level. Choice D (IV 40mg Furosemide) is a diuretic that would worsen this patient’s dehydration and acute kidney injury. This patient has severe hyponatremia along with neurological symptoms (coma and seizure). Hyponatremia plus neurologic symptoms, like vomiting, seizures, reduced consciousness, cardiorespiratory arrest, necessitate rapid correction of sodium with hypertonic (3%) NaCl solution. 3% NaCl solution can be infused 100-150mL over 15-20min and repeated up to 3 doses total. A serum sodium level should be measured after each administration of 3% NaCl in order to limit the increase in the sodium level to no more than 8-12 mEq/L over the first 24hours. This is done to reduce the risk of osmotic demyelination syndrome. Correct Answer: C