Ans. a. Isotonic crystalloidRef: Harrisons Principle of Internal Medicine 19th Ed; Page No-2096Aggressive intravenous fluid resuscitation; is the most important treatment intervention for acute pancreatitis.For rest the pancreas; the patient is made NPO and to control abdominal pain narcotic analgesics given intravenously and supplemental oxygen (2L) via nasal cannula.To maintain urine output>0.5cc/kgper hour; Intravenous fluids of lactated Ringers or normal saline are initially bloused at 15-20cc/kg(1050-1400ml), followed by 3 mg/kg per hour (200-25mL/h).Serial bedside evaluations are required every 6-8 h to asses vital signs, oxygen saturation, and change in physical examination.Lactated Ringers solution may be a better crystalloid than normal saline because it decreases systemic inflammation.