What is the hollow section of metal that runs along the outermost section of the floorboard called?

The correct choice refers to the rocker panels, which are structural components of a vehicle that are located along the sides, typically near the bottom of the vehicle's body. These hollow sections of metal serve several important functions, including providing structural integrity and support to the vehicle's body, aiding in crash safety, and also helping with the aesthetics of the vehicle's design.

Rocker panels are particularly significant in situations involving vehicle extrication because they can become compromised in collisions. Understanding their location and role is crucial for rescue personnel when performing vehicle stabilization and extrication techniques.

While the chassis represents the underlying structure of the vehicle, which includes all the components that support the vehicle in motion, it does not specifically refer to the hollow sections along the sides. Frame rails are more concerned with the structural framework that supports the vehicle's load and suspension, while the fender is an external body component that covers the wheel well. Hence, rocker panels are the most accurate term for the specific hollow section along the outermost floorboard area.