Which of the following could cause hypoxia?

Hypoxia, which refers to inadequate oxygen supply to the body's tissues, can be caused by the obstruction of the airway. When the airway is obstructed, oxygen cannot flow into the lungs, leading to decreased oxygen availability for gas exchange. This effectively prevents sufficient oxygen from entering the bloodstream, which can result in hypoxia as the body's tissues are deprived of the oxygen they need to function properly.

While other factors, such as ventilation-perfusion mismatch or decreased pH levels, can also contribute to problems with oxygen transport and utilization, airway obstruction directly impedes the entry of oxygen into the lungs. Therefore, addressing an obstructed airway is critical in emergency medical situations to quickly restore oxygen supply to the body and prevent hypoxic conditions.