Which of the following is a treatable cause of cardiac arrest?

Hypoxia is a treatable cause of cardiac arrest because it refers to a deficiency of oxygen in the body's tissues. In cases of cardiac arrest, restoring adequate oxygen levels can be crucial for survival and recovery. This is typically addressed through immediate interventions such as administering supplemental oxygen or performing successful ventilation, which can help re-establish normal oxygen levels in the bloodstream and support return of spontaneous circulation.

In contrast, obesity, excessive exercise, and age-related factors mainly contribute to overall health risks and may predispose individuals to cardiac events, but they are not directly treatable causes of cardiac arrest in the acute setting. Addressing those factors typically requires long-term lifestyle changes and management, rather than immediate interventions that can reverse a current cardiac arrest situation.