Final answer:
Compression sleeves for ACSR conductors have a gripping unit that is molded to the aluminum sleeve. Meanwhile, high-voltage transmission lines are not insulated; air acts as the insulator.
Step-by-step explanation:
Compression sleeves are manufactured for transmission line ACSR conductors that contain a gripping unit that is molded to the aluminum sleeve. The correct answer is c. Molded.
As for the statement about high-voltage wires, it is false. The high-voltage wires, or transmission lines, that are connected to tall metal-frame towers are held aloft by insulating connectors, but these wires themselves are not wrapped in an insulating material. High-voltage transmission lines are typically made of aluminum (for conductivity) and steel (for strength) and are not insulated because the air surrounding them acts as an insulator, and it would be prohibitively expensive and impractical to wrap them due to the high voltages involved.