A nurse is caring for a client who was admitted to the unit three hours ago following a total hip arthroplasty. Which of the following findings should be the nurse's priority concern?
A. Urinary output of 75 mL over the past 3 hr
B. 8-point elevation in the pre-surgery diastolic blood pressure
C. Oxygen saturation of 90% on oxygen at 2 L per nasal cannula
D. Core body temperature of 36.2° C (97.2° F)