What is the primary purpose of the National Electrical Code (NEC)?

The primary purpose of the National Electrical Code (NEC) is to establish safety standards for electrical installations. This code is designed to ensure that electrical wiring and equipment are installed safely to protect people and property from electrical hazards such as fires, shocks, and other dangers. By setting guidelines for safe practices, the NEC helps to create a standardized approach to electrical work, which enhances safety across the industry.

While the other options mention relevant aspects of electrical practices, they do not capture the main intention of the NEC. Regulating prices of materials or promoting electrical devices are not within the scope of the NEC's objectives. Additionally, while the NEC does provide guidelines that can assist electrical engineers, its primary focus is on safety standards rather than being a reference solely for engineering practices. Thus, emphasizing safety standards reflects the central role the NEC plays in electrical installations and the protection it aims to provide.