Which of the following best defines a structural member in a facility?

A structural member in a facility refers specifically to any component that supports or transfers loads, ensuring the stability and integrity of the building. These elements are fundamental in maintaining the structure's form and function, and include beams, columns, floors, and walls designed to support weight.

The other options, while they may be part of a building, do not qualify as structural members. Insulation panels often serve a thermal regulation purpose and are not designed to carry structural loads. Exterior siding primarily serves as a protective and aesthetic outer layer and does not contribute to the load-bearing capacity of the building. Interior decor elements, such as paint, furnishings, or artwork, do not have any structural function and are included for aesthetic purposes only.

Thus, the best definition for a structural member is any load-supporting member, as it encompasses all parts of a structure that contribute to its ability to support its own weight and withstand external forces.