Final answer:
The statement about high-voltage wires being wrapped in insulating material is false. They are held aloft by insulating connectors, and the surrounding air acts as the insulator. Option number b is correct.
Step-by-step explanation:
The statement that high-voltage wires are wrapped in insulating material is false. High-voltage power lines, which are the wires connected to tall metal-frame towers, are typically not covered with insulating material. The air around these wires acts as a natural insulator.
Instead of insulation, these power lines are held aloft by insulating connectors, often made from materials like porcelain or glass, which are designed to prevent electrical currents from traveling down the towers.