Correct option is B
A box girder is a structural beam that consists of two or more webs and enclosed spaces, forming a box-like cross-section. These girders are commonly used in bridges, cranes, and other large-span structures where strength, stability, and resistance to torsion are crucial.
Detailed Explanation:
1. Plate Girder: These are simple girders with a single web plate and flanges, typically used for smaller spans.
2. Box Girder: Comprises multiple webs and forms a hollow, box-shaped cross-section, providing high resistance to bending and torsion.
3. Gantry Girder: These girders support moving loads, like cranes, and typically have a single web.
4. Balanced Girder: This is not a standard term in structural engineering and is rarely used in practical contexts.
