Differentiated ownership of buildings means that according to the use function, a building is structurally divided into a special part used by each owner alone and a common part used by multiple owners. Each owner has the combination of the exclusive right to its exclusive part and the common right to the common part. Among them, the proprietary part refers to the independence of structure and use, and can become the object of separate ownership. The common part refers to the distinction between the other parts of the building other than the separate part owned by the owner and used by multiple owners.
According to the above definition, which of the following is a proprietary part of a building?
corridor