What is a characteristic feature of the primary components in a box girder?

Answer: B — Multiple webs for strength

A characteristic feature of the primary components in a box girder is the presence of multiple webs for strength. Box girders are designed with a closed cross-section that typically includes two flanges at the top and bottom and vertical web components connecting these flanges. This design serves to enhance the girder's structural integrity and load-carrying capacity, making it particularly well-suited for carrying heavy loads over long spans. The multiple web components help in distributing loads more evenly and improving the stiffness of the girder, which is crucial for maintaining structural stability and minimizing deflections. As a result, the use of multiple webs leads to a more efficient and robust design compared to a girder with a single web or other configurations. This characteristic is integral to the functionality and performance of box girders in bridge construction.