The nurse is caring for a patient in the acute care setting with a spinal cord injury (SCI) at the level of C-3. What is the main cause of complications or death related to this level of injury?

A. Hypertension is less common and not the primary cause of death at this injury level. B. Bradycardia can occur but is not the leading cause of mortality. C. Injury at C-3 can impair diaphragm function due to phrenic nerve involvement, leading to respiratory failure, which is the main cause of complications and death. D. Septic shock can occur but is not the primary immediate risk.