Answer:
supervisors
Step-by-step explanation:
A chartered city, county or, municipality works on a unique set of laws which form the legal foundation for it's government at the local level. A document called a charter stipulates and articulates laws such as this.
A board of supervisors in a chartered county refers to a governmental body that oversees the operation of county government. Systems such as this are present in the American states like: Arizona, California, Iowa, Mississippi, Virginia, and Wisconsin, as well as 16 counties in New York.