// EMT Question · Airway, Respiration & Ventilation
The correct OPA size is determined by measuring from:
A. Tip of the nose to the earlobe
B. Corner of the mouth to the angle of the jawCorrect
C. Corner of the mouth to the earlobe
D. Center of the lips to the chin
// Rationale
OPA size is measured from the corner of the mouth to the angle of the jaw (or from the earlobe to the corner of the mouth).