A sentinel event is a patient safety event that reaches a patient and results in any of the following:
* Death
* Severe temporary harm
* Permanent harm
* An intervention required to sustain life
Option D, "An intervention to sustain life," aligns with the definition of a sentinel event. Such interventions may include actions like cardiopulmonary resuscitation (CPR), defibrillation, or other emergency procedures necessary to keep the patient alive following a significant adverse event.