Placing a phrenic nerve pacing electrode in the thorax above the pericardium rather than in the neck is preferable because 

A. an examination of the entire intrathoracic nerve is possible. 
B. the incision will be closer to the radio frequency receiver pocket.
C. injury to the thoracic duct is avoided.
D. most patients have sustained a cervical fracture.
E. the phrenic nerve at this point includes the accessory phrenic nerve. 

Answer E

For proper diaphragmatic pacing the pacing electrode should be placed in the thorax above the pericardium to insure that the accessory phrenic nerve is not excluded. This nerve, a branch of the fifth cervical nerve, joins the main phrenic nerve at or below the level of the clavicle in approximately 75% of cases. An examination of the entire intrathoracic nerve is not necessary since preoperative confirmation of the integrity of the nerve by transcutaneous phrenic nerve stimulation is mandatory prior to surgery. The relationship of the incision to the radio frequency receiver pocket and injury to the thoracic duct are not concerns. While it is true that most patients have sustained cervical fractures, this only mandates special care during intubation for general anesthesia.