Final answer:
A broker shall provide a 'High level of supervision' for all licensees, including brokers, dealers, and bankers who are licensed to sell securities.
Step-by-step explanation:
In the context of the question, a broker providing a 'High level of supervision' is responsible for supervising all licensees. The term 'licensees' refers to the individuals who are licensed to sell securities and includes brokers, dealers, and bankers. As per the information provided, the regulator of securities sales and brokerage is responsible for overseeing and supervising licensees to ensure compliance with regulations and maintain a high level of professionalism and ethics in the industry.