Which of the following persons must have a real estate broker's license in order to transact business?

The reasoning behind the correct answer relates to the legal requirements for engaging in real estate transactions. A person must have a real estate broker's license when negotiating or conducting business related to real estate on behalf of someone else, especially when it involves compensation or a fee.

In the scenario described, a person negotiating the sale of their parent's residence, even with written authority, is acting on behalf of another individual and thus requires a broker's license. This requirement ensures that transactions involving real property are handled by individuals who are formally trained, knowledgeable about the laws, and accountable in real estate dealings.

On the other hand, the other scenarios do not meet the criteria for needing a broker's license. An owner of a six-plex managing their own property is not required to have a broker's license since they are transacting on their own behalf. The superintendent of a large apartment building who shows apartments as part of their job is typically an employee of the property owner and is not acting independently as a real estate broker. Lastly, a person negotiating the sale of an entire business, whether involving real estate or not, would typically fall under different business regulations rather than requiring a real estate broker's license.

Thus, option D correctly identifies a situation that necessitates a real