A postoperative client exhibits a sudden onset of shortness of breath accompanied by syncope when getting up to a chair. The nurse assists the client into the bed and performs an assessment which reveals a heart rate of 110 beats/min and a blood pressure of 88/56 mm Hg. The client appears cyanotic and has distended neck veins. What is the nurse's first action?
A) Administer oxygen.
B) Assess breath sounds.
C) Notify the Rapid Response Team.
D) Perform pulse oximetry.