Final answer:
The licenses of brokers and affiliate brokers usually need to be on file with the principal broker, who oversees compliance with real estate laws.
Step-by-step explanation:
The licenses of all brokers and affiliate brokers are a testament to their professional qualifications and adherence to industry standards. According to real estate regulations, which may vary by jurisdiction, these licenses are most commonly required to be on file with the principal broker. the principal broker is responsible for overseeing the brokerage activities and ensuring compliance with real estate laws.
Therefore, option D is usually the correct answer, as the licenses should be maintained at the broker's office and not necessarily carried by brokers or filed with the Real Estate Commission.