A nurse is triaging clients following a mass casualty event. Which of the following clients should the nurse assess first?

Choice A reason: A massive head injury with no responsiveness indicates nonsurvivable injury. In mass casualty triage, resources are directed to those who can benefit. This client would be categorized as expectant, not immediate. Choice B reason: Severe stridor and tracheal deviation indicate airway obstruction and tension pneumothorax, both life-threatening emergencies. This client requires immediate intervention to secure the airway and prevent death. This is the highest priority. Choice C reason: An open fracture is serious but not immediately life-threatening. The client is stable and can wait for treatment after airway emergencies are addressed. Choice D reason: A small partial-thickness burn is minor and not life-threatening. This client is the lowest priority in triage.