When Assessing the Pulse of a 6-Year-Old Boy,the Nurse Notices

When assessing the pulse of a 6-year-old boy,the nurse notices that his heart rate varies with his respiratory cycle,speeding up at the peak of inspiration and slowing to normal with expiration.The nurse's next action would be to:

A) notify the physician immediately.
B) consider this a normal finding in children and young adults.
C) check the child's blood pressure and note any variation with respiration.
D) document that this child has bradycardia and continue with the assessment.