Which of the following is a business organization that involves two or more individuals working for a common nonprofit purpose?

The correct answer is an unincorporated association because this type of business organization consists of individuals who come together for a common nonprofit purpose. Unincorporated associations do not have a formal structure like a corporation and are characterized by the collaborative efforts of members working toward a mutual aim that does not involve distributing profits among members.

In contrast, a partnership involves two or more individuals who agree to operate a business for profit, making it distinct from the nonprofit focus of an unincorporated association. A sole proprietorship is operated by a single individual, and while it can be a simple and direct form of business, it does not involve multiple people working together in a nonprofit capacity. A corporation is a more formal legal entity that is created for conducting business and usually aims for profit generation, making it incompatible with the concept of a nonprofit purpose as mentioned in the question.