What activities take place in the main factory building?

The primary focus of a factory building is centered on production processes, which typically includes all manufacturing and filling operations of products. Selecting this option highlights the main function of the factory as a workspace specifically designed for these activities. In this context, "all production and filling of tanks" demonstrates a comprehensive view of the factory's role within the larger production system, emphasizing that the factory is where the actual creation of goods occurs, along with the assembly and preparation of those products for distribution.

Packaging and shipping, while critical operations, often take place in separate areas or facilities dedicated specifically to those functions. Similarly, maintenance of equipment is essential for the factory's operation but is generally conducted in designated maintenance areas rather than the main production space itself. Storage of materials is also crucial, but it is typically considered a support operation rather than the core purpose of the main factory building. Thus, the correct answer reflects the primary activities that define the factory's operational identity.