What type of properties does a broker NOT need a license to sell if they are personally owned?

A broker is not required to hold a license when selling properties that they personally own. This principle is grounded in real estate regulations that often allow individuals to engage in the sale of their own properties without obtaining a broker's license.

In the context of the question, the correct choice accurately reflects the idea that ownership plays a significant role in the licensing requirement. When a broker personally owns properties, they are engaging in private transactions rather than acting on behalf of another party, which is what typically necessitates a license.

Other options concern various types of properties or quantities but do not accurately capture the essence of personal ownership. Whether the properties are residential, commercial, or simply a number greater than 20, if they are owned personally, the requirement for a broker's license is waived, validating the correctness of the chosen answer.