Which of the following refers to relay or logic elements for protective functions?

The term that best fits the description of relay or logic elements used for protective functions is Protective Device. Protective devices are specifically designed to monitor electrical systems and detect fault conditions such as overloads, short circuits, or other abnormalities. These devices utilize relays and logic elements as integral components that facilitate prompt action to isolate faulty circuits or equipment, thereby protecting both the system and the personnel involved.

In the context of electrical systems, protective devices are crucial for ensuring safety and preventing damage to equipment by automatically disconnecting power in the event of a fault. Their operation is based on principles of protection coordination and relay logic, making them synonymous with the defined role of relay elements in protective applications.

Other options like safety switches, control relays, and electrical breakers do serve important functions within electrical systems, but they do not exclusively embody the comprehensive definition provided in the question as well as protective devices do. Safety switches and electrical breakers typically focus on isolating circuits from loads while control relays are more about controlling operations rather than performing protective functions in the way that protective devices do.