Final answer:
Condominium ownership is most commonly represented by a deed, a legal document that states the owner's rights and title to an individual unit within a property.
Step-by-step explanation:
Condominium ownership is most commonly represented by a deed. This legal document signifies the owner's title to the individual unit within a larger property and includes specifics such as the boundaries of the unit, rights to common areas, and any encumbrances or restrictions. Unlike a stock, which represents ownership in a corporation, or a bill of sale, which is used for transferring ownership of personal property, a deed is used specifically for real estate transactions. Owning a condo allows individuals to have their personal space while sharing costs and responsibilities for common areas with other unit owners, similar to how a sole proprietorship allows an individual to own and operate a business independently.