Concept:Choking occurs when an object blocks the airway, cutting off oxygen to the brain. Immediate first aid aims to dislodge the object quickly.Explanation:The American Red Cross recommends a “five-and-five” approach. First, stand behind the person and give five sharp back blows between the shoulder blades using the heel of your hand. Then, perform five abdominal thrusts (Heimlich manoeuvre). Alternate between back blows and thrusts until the object is removed. Do not try to remove the object with a finger because it may push it deeper. Calling an ambulance or giving a drink delays critical action. The correct first step is to give five sharp back blows.Answer:B. Give five sharp back blows between shoulder blades