Final answer:
The duties of an expanded-functions dental assistant can vary based on the state or province, as these are regulated by local laws which dictate their scope of practice.
Step-by-step explanation:
The statement that the duties of an expanded-functions dental assistant (EFDA) can vary according to the state or province is indeed true. The scope of practice for EFDAs is regulated by state or provincial laws, which means the allowed procedures, level of supervision required, and certification processes can be different from one region to another. For instance, in some areas, EFDAs may be allowed to perform complex tasks such as placing and shaping fillings, while in other regions, they may be restricted to more basic supportive duties.