The client has developed atrial fibrillation

The client has developed atrial fibrillation. The heart rate is 142 beats/min. Which is the priority action for the nurse to take? select one

a) check bilateral capillary refill of the feet

b) instruct the client to take a deep breath and hold it

c) administer lidocaine 100 mg intravenously

d) assess level of consciousness and orientation