What is a feature of every seat on the aircraft?

Every seat on the aircraft is equipped with a table tray and seat back. This feature is essential for passenger comfort and functionality during flights, as it provides a space for passengers to place items such as food, drinks, and personal belongings. The table tray enhances the in-flight experience, allowing for more flexibility in how passengers utilize their seating area.

Other features such as inflatable life vests or personal entertainment systems may not be present in every seat. For instance, not all aircraft configurations include personal entertainment systems for each seat, and inflatable life vests are typically found only on specific seat types or in certain cabin classes. Adjustable headrests can enhance comfort, but they are often an optional feature rather than a standard one across all seats. Therefore, the presence of a table tray and seat back is a universal aspect that applies to every seat, making it the correct choice.