What information must an advertisement for a freelance business display?

The correct answer emphasizes the importance of transparency and accountability in the freelance business sector. Displaying the practitioner's certificate number and freelance authorization number is critical because it verifies the individual's qualifications and legal compliance to practice in that field. This information assures potential clients that the freelance professional is recognized by relevant authorities and possesses the necessary certifications to operate legally. In regulated industries, this transparency builds trust and confidence among customers, who can verify the professional's credentials and ensure that they are hiring someone qualified.

Having this information prominently displayed distinguishes the professional in a market where many may lack proper credentials. It can also protect consumers from fraud or unqualified practitioners, making it a vital element of any advertisement in the freelance sector.

Displaying the other options, while potentially beneficial, does not serve the same essential function of establishing legitimacy and compliance with regulatory standards that the certificate and authorization numbers do.