You are at the scene of a multiple-casualty incident where a church van carrying 15 parishioners overturned. You and your partner are in charge of the treatment unit and are presented with four patients. Which one will you treat first?

A) A confused 69-year-old male with a respiratory rate of 42 breaths/min and a rapid and weak radial pulse
B) An elderly female patient with a femur fracture and a yellow tag on her wrist
C) A 21-year-old male in cardiopulmonary arrest
D) A 13-year-old boy who walked to the treatment area complaining of a severe headache

A) A confused 69-year-old male with a respiratory rate of 42 breaths/min and a rapid and weak radial pulse