The paramedic has responded to a motor vehicle collision. While approaching the vehicle he notes a large circular crack in the windshield. Upon reaching the vehicle he finds a middle-aged female lying unrestrained on the floor of the vehicle with a significant pool of blood around her head. The pt's pulse is rapid and thread, her capillary refill is slow and she does not respond to verbal stimuli. Suspecting a head injury, which of the following treatments is considered to be the primary first line therapy for pt with a suspected head injury?

A) Hyperventilate the pt to increase circulating CO2 levels
B) Repeat vital signs every 5 min to monitor for pulmonary edema
C) Initiate 2 large bore catheters of normal saline for medication ports
D) Administer high flow oxygen to encourage oxygen uptake by the hemoglobin