Which of the following is included in state regulatory agencies?

State regulatory agencies, specifically state boards of cosmetology, are crucial entities responsible for overseeing and enforcing regulations related to the practice of cosmetology within their specific state. This includes licensing manicurists and ensuring that all practitioners adhere to safety and sanitation standards to protect public health and welfare.

State boards of cosmetology are tasked with establishing the educational requirements, examinations, and continuing education needed for licensure. They also handle disciplinary actions against licensed professionals who violate regulations or ethical standards. This regulatory framework is essential in maintaining a consistent quality of service and safety in the beauty industry, including manicuring.

The other options listed do not serve the same regulatory purpose within the field of cosmetology. Insurance companies, private corporations, and national agencies are involved in their respective roles but do not have the regulatory authority that state boards of cosmetology possess regarding the practice within a state. Therefore, the inclusion of state boards of cosmetology as state regulatory agencies is vital for understanding the governance of the manicurist profession.