A 72-year-old postoperative patient after major surgery has urine output of 10 mL/hour for the last 3 hours. Blood pressure is 105/65 mmHg, heart rate 100/min, mucous membranes slightly dry. What is the most appropriate initial management?ADo nothing; low urine output is normal after surgeryBGive a fluid challenge with IV crystalloid and reassess urine output and observationsCInsert dialysis catheter immediatelyDIncrease Furosemide doseERestrict fluids furtherCheck my answer