You respond to a 72-year-old man with syncope. He is sitting in the kitchen when you arrive. He is alert and oriented to person, place, and time. He complains of dizziness. Current vitals are BP 108/60, pulse 96 slightly irregular, and respirations of 28. Pulse oximeter reading is 97%. ECG shows a sinus rhythm with occasional PVC's. This patient should receive oxygen

(A) by nasal cannula at 3 LPM.
(B) by nonrebreather mask.
(C) oxygen application is not required.
(D) by nasal cannula at 6 LPM.

Answer: (B) by nonrebreather mask.