Final answer:
The Private Security and Investigative Services Act requires that all private security workers, including some who were not licensed previously, must be licensed. This ensures that individuals in the private security industry adhere to professional standards and regulations.
Step-by-step explanation:
The question pertains to the requirements set forth by the Private Security and Investigative Services Act, which stipulates that private security workers are required to be licensed. The correct answer to the student's question is C. To be licensed including some who were not licensed previously. This means that all individuals working in private security must obtain a proper license, and this requirement extends to some individuals who may not have needed a license under past regulations. It is mandatory, irrespective of their previous experience, to ensure that all practicing individuals meet current professional standards and regulations.