What is assembled in a factory and delivered to the construction site?

The correct answer is a truss. Trusses are structural frameworks typically used to support roofs or bridges and are commonly prefabricated in a factory setting. This process ensures precision and quality, as the components are manufactured using consistent materials and techniques. Once assembled, they are transported to the construction site, where they are installed.

In contrast, rafters are usually cut and installed on-site rather than prefabricated in a factory. Framework typically refers to the assembly of various components on-site to create the skeletal structure of a building. Columns can also be prefabricated, but they do not have the same comprehensive factory assembly process associated with trusses, which are specifically designed to span larger distances and support significant loads. Thus, the distinctive factory assembly and site delivery characteristic makes trusses the most suitable answer.