A 68-year-old woman presents to the emergency department with fever, hypotension, tachycardia, and suspected pneumonia. Her lactate is 4.0 mmol/L and mean arterial pressure is 58 mm Hg after an initial 500 mL crystalloid bolus. She weighs 80 kg. According to the Surviving Sepsis Campaign, which initial fluid resuscitation order is most appropriate?