After eating at a local restaurant, a 20-year-old male complains of blurred vision, difficulty speaking, and difficulty breathing. He is conscious; however, his respirations are profoundly labored and producing minimal tidal volume. You should:
A. position him supine and elevate his legs.
B. apply oxygen via a nonrebreathing mask.
C. assist his ventilations with high-flow oxygen.
D. request a paramedic to administer atropine.