Which of the following statements is true regarding ENT installations?

The selected answer is indeed the correct choice because it highlights the necessary requirement that Electrical Nonmetallic Tubing (ENT) must be installed using appropriate couplings and connectors to ensure a safe and reliable installation. ENT is utilized in various electrical applications, and using the correct fittings is critical for maintaining the structural integrity of the installation, ensuring that the tubing is securely connected, and that it adheres to applicable code regulations. Proper couplings and connectors facilitate seamless transitions and connections between different sections of ENT, as well as between the ENT and other electrical components, helping to prevent damage and potential hazards.

The other statements do not accurately reflect the code requirements or standard practices. For instance, ENT can indeed be supported but does not necessarily stand alone without any form of support, as support is typically required to maintain its structural integrity. Furthermore, while ENT fittings can be made of various materials, there is no strict requirement that all fittings must be metal. Finally, stating that ENT installations do not require any fittings is incorrect since proper fittings are essential for ensuring effective and reliable electrical installations.