A Trauma Nurse Has Responded to the Scene of a Mass

A trauma nurse has responded to the scene of a mass casualty incident.The nurse sees several injured patients lying together in a heap.One of them does not appear to be breathing.What action by the nurse takes priority?

A) Put on personal protective equipment.
B) Assess the non-breathing patient first.
C) Determine if the scene is safe to enter.
D) Open the non-breathing patient's airway.