Final answer:
High-voltage wires are supported by insulating connectors but are not wrapped in insulating material, making the statement false (option b). Air serves as the insulator for these bare wires.
Step-by-step explanation:
The statement that the high-voltage wires connected to tall metal-frame towers are held aloft by insulating connectors and are wrapped in an insulating material is false. High-voltage wires are indeed supported by insulating connectors to prevent electrical current from traveling down the tower structure. However, these wires themselves are not typically wrapped in insulating material. Instead, they are left bare and are insulated from the ground and other conductive materials by air and the insulating connectors that support them.
The air around the wires serves as the insulating medium at such high voltages, making additional insulation unnecessary and impractical due to the nature of the electrical grid and the immense size of the wires.