You Arrive on the Scene of a Two-Car Motor Vehicle

You arrive on the scene of a two-car motor vehicle collision. The patient was the unrestrained driver of a car that struck another from behind at 25 mph. In the course of the collision, the patient flew forward and struck the windshield with his head. No air bags were deployed. The patient extricated himself and denies head, neck, or back pain; however, you do note a small cut on his hand, which occurred as he was getting out of the car. When asked about preexisting medical problems he tells you that he did have herniated disks in his lumbar spine that were surgically repaired several years ago. Based on this, your strongest reason to fully immobilize this patient would be:

A) history of back surgery.
B) laceration to the hand.
C) self-extrication of the patient.
D) mechanism of injury.