Which condition must be met to occupy an Exit Seat on an airplane?

To occupy an Exit Seat on an airplane, passengers must meet specific criteria to ensure their suitability for the role. This includes being of a certain age, typically at least 15 years old, and being able-bodied, which means they should have the physical ability to assist in an emergency evacuation if necessary. This requirement is critical because Exit Seats are designated for passengers who may need to help operate the emergency exits and assist others during a situation that requires evacuation. By ensuring that these seats are occupied by individuals who have the capacity to respond effectively, airlines prioritize passenger safety and compliance with regulations governing emergency procedures.

The other options do not fully address the essential criteria established for the Exit Seat occupation. For instance, no special requirements would undermine the safety protocols necessary for managing emergency situations, and traveling with an adult or purchasing a first-class ticket does not inherently relate to a passenger's ability to perform required duties.