How frequently should a continuous metal gravel guard be bonded to the system when adjacent to a roof perimeter cable?

The correct choice indicates that a continuous metal gravel guard should be bonded to the lightning protection system at each downlead location. This approach ensures that the guard effectively contributes to the overall lightning protection by minimizing impedance and enhancing current transfer during a lightning strike. Bonding at each downlead provides multiple paths for the electrical charge to safely dissipate into the ground, which is essential for preventing damage to the structure and ensuring safety.

By bonding at these specific points, the system can maintain integrity and functionality, especially in areas where there may be a concentration of electrical energy. This connection strategy is critical for ensuring that there are no weak points in the protective system that could lead to potential failures during a lightning event.