Which of the following is NOT a county officer mentioned in the Arizona Constitution?

The correct choice identifies that the "County clerk" is not a specific county officer mentioned in the Arizona Constitution. The Arizona Constitution outlines the roles of various county officers, including the county treasurer, county sheriff, and county assessor, which are recognized as part of the statutory framework for Arizona's local government structure.

The inclusion of the county treasurer, county sheriff, and county assessor in the state's governance reflects the essential roles these positions play in managing finances, law enforcement, and property assessments at the county level. However, while the function of a clerk may exist in counties, it is not explicitly designated as a constitutional office in Arizona's foundational governing document. This distinction emphasizes the specific roles assigned within the constitutional context rather than broader administrative functions, which may vary by county regulations or policies.