Which of the following activities is NOT permitted for someone holding a salesperson's license?

Owning a substantial interest in a real estate firm is not permitted for someone holding a salesperson's license. Generally, in the realm of real estate, the law dictates that a salesperson must operate under the supervision of a licensed broker. The broker is the one who holds the responsibility for the actions of the salesperson as well as for ensuring compliance with all real estate laws.

Salespersons are typically employed or associated with a broker who is the legal entity to which the clients and transactions are ultimately tied. A salesperson's role focuses on aiding clients in buying, selling, or leasing properties, which includes activities such as listing properties, showing homes, and representing clients in negotiations.

In contrast, only licensed brokers can own substantial interests in a real estate firm, as they have the required qualifications and regulatory oversight to manage a brokerage business. This structure helps maintain professional standards and ethical practices within the real estate industry, ensuring that salespersons remain accountable to their brokers and the law.