The nurse is caring for a patient who sustained a spinal cord injury (SCI) at T1. The alarm on the monitor sounds because the patient's blood pressure is 86/50 and the heart rate is 44. The nurse's priority action would be to:

A. Reverse Trendelenburg position may lower blood pressure further, worsening hypotension. B. IV fluids might be needed but should be given after assessment and provider order. C. Asking patient care tech to check delays the nurse’s direct assessment, which is critical. D. Immediate assessment and verification of vital signs are essential to determine the cause of hypotension and bradycardia, common in SCI patients due to neurogenic shock, and to initiate appropriate interventions promptly.