A nurse is helping to triage a group of clients at a mass casualty incident who were involved in an explosion at a local factory. Which of the following clients should the nurse tag to be the priority for care?

A female who is pregnant at 20 weeks of gestation, has multiple cuts and abrasions, and is walking around

A client who has a simple fracture of the femur, multiple scratches on both legs, and is crying hysterically

A client who has severe head injuries, respiratory rate 8/min, and is unresponsive

A client who has a piece of wood punctured into the chest wall and has an audible hissing sound coming from the wound