How is fuel weight supported in bladder-type fuel cells?

Bladder-type fuel cells are designed to hold fuel within a flexible container, known as a bladder, which is made from fabric or some other flexible material. The correct assertion about how fuel weight is supported in these types of fuel cells is that the bladder is supported by the aircraft structure.

When the bladder is filled with fuel, its weight presses downwards, and this weight is transferred to the aircraft's structure around the fuel cell. The bladder does not possess inherent structural support itself; rather, it relies on the structure of the aircraft to support the weight of the fuel it contains. This setup allows for a flexible and lightweight solution to fuel storage, while also ensuring that the weight is managed properly within the airframe design.

Other options discuss aspects like built-in support or structural additions that do not accurately represent how bladder-type fuel cells operate. The emphasis on the aircraft structure being the support system reflects the design intent behind these fuel cells, making option A the correct and most accurate answer.