Final answer:
During CPR, the rise of the patient's chest is the correct sign that you have achieved adequate ventilation, indicating proper pulmonary ventilation and facilitating external respiration.
Step-by-step explanation:
The question pertains to the signs of effective ventilation during CPR. When performing CPR, knowing whether you have achieved adequate ventilation for a patient is crucial. The correct answer is C. Rise of the chest. When you administer rescue breaths, the chest should rise, indicating that air is entering the lungs and not the stomach, which is a sign of proper pulmonary ventilation. Witnessing the rise and fall of the chest suggests that air is passing through the trachea into the lungs, facilitating external respiration. This is the primary goal of rescue breathing in CPR - to ensure oxygen reaches the alveoli where gas exchange occurs. Air escaping the nose, air entering the stomach, or hearing a popping sound are not reliable indicators of adequate ventilation.