When providing first aid to a victim of gas poisoning, what is the MOST important symptom to check for?

Correct Answer: Option A — suspension of breathing

The primary danger in gas poisoning is respiratory failure. Immediate assessment of breathing is critical because the cessation of respiration leads to rapid brain damage. Establishing an airway and initiating artificial respiration takes precedence over other symptoms, as oxygenation is the most urgent requirement for the victim's survival.