Which type of construction project is classified as a commercial project?

The classification of commercial projects generally excludes residential properties and encompasses types of construction that are meant for business use or income generation. Option C correctly identifies a project that is specifically described as excluding residential duplexes, tri-plexes, or four-plexes, categorizing it as a commercial project.

In the context of construction, commercial projects typically include buildings such as offices, retail stores, hotels, warehouses, and similar structures that serve business purposes. Because option C specifies the exclusion of specific types of residential buildings, it aligns directly with the characteristics of commercial projects, which focus solely on non-residential construction.

The other options involve residential properties. Option A deals with residential homes, which are clearly not commercial. Option B refers to a single residential duplex, thereby categorizing it as a residential project. Option D mentions projects on vacant land only, which does not define whether the intended development would be commercial or residential, leaving it ambiguous. This vagueness makes it unsuitable for classification as a commercial project without further context or specification regarding the intended use of the land.