An elderly man is found lying unresponsive next to his bed. The patient's wife did not witness the events that led to his unresponsiveness. You should immediately:

A) assess the patient's respirations.
B) apply 100% supplemental oxygen.
C) tilt the head back and lift up the chin.
D) grasp the angles of the lower jaw and lift.

Answer: D) grasp the angles of the lower jaw and lift.