What must be ensured by the life preserver in relation to each occupant?

The life preserver must be easily reachable and removable for each occupant to ensure prompt accessibility in an emergency situation. In the event of a water landing or other emergency where quick evacuation is necessary, having a life preserver that occupants can quickly grab and don increases their chances of survival. It is crucial that the safety equipment on board is designed for ease of use, allowing passengers to respond swiftly without delay.

In contrast, options that suggest keeping the life preserver difficult to access or stored away in a compartment would hinder immediate availability during emergencies, which is contrary to safety protocols. The requirement for life preservers emphasizes the need for them to be within reach and intuitive to use, making the correct choice about accessibility and ease of removal vital for passenger safety. Additionally, being permanently attached to the seat would not typically facilitate quick access, posing a further risk during critical moments.