You have responded to a bar for a fight involving approximately 20 patrons. Weapons were used and all the patrons have varying degrees and types of injuries. You are in charge of triage and must use the Simple Triage and Rapid Transport (START) system. You find a young person lying on the floor with blood covering his shirt. Quick assessment reveals him to be breathing at 24 times per minute. Which one of the following should you do next? A) Determine the mental status
B) Place a yellow tag on his wrist
C) Start positive pressure ventilation
D) Check for a radial pulse