You are dispatched to a local mall, where you are met by bystanders who state that the patient was talking to a customer representative when she "passed out." You find an alert and oriented 55-year-old female patient lying supine on the tile floor. The patient tells you that the back of her head is hurting, her neck now hurts, and her arms and legs feel very weak. Which action should you perform first?

A) Open her airway with a jaw-thrust maneuver
B) Obtain a full set of vital signs
C) Take manual cervical spine motion restriction
D) Assess the back of the patient's head for injury

C) Take manual cervical spine motion restriction