*Question G0B11:
Which of the following is required for lightning protection ground rods?*  

*Correct Answer is  D: They must be bonded together with all other grounds*  

### AI Response: (may contain errors)  

For effective lightning protection, it is crucial to ensure that all ground rods are bonded together with all other grounds. This creates a single, unified grounding system that helps to equalize potential differences and safely dissipate lightning energy into the earth.

### Explanation:

1. **Correct Answer (D):**  
   - **Bonding all grounds together** ensures that there is a low-resistance path for lightning energy to travel. This minimizes the risk of potential differences between different parts of the grounding system, which could otherwise lead to dangerous voltage levels and possible equipment damage or personal injury.

2. **Why Other Choices Are Incorrect:**
   - **Choice A:** Bonding to all buried water and gas lines is not a requirement for lightning protection. In fact, connecting to gas lines can be dangerous due to the risk of igniting gas leaks.
   - **Choice B:** Bends in ground wires should be gradual, not right angles. Sharp bends can increase inductance and impedance, reducing the effectiveness of the grounding system.
   - **Choice C:** Lightning grounds should not be connected to ungrounded wiring. This could introduce high voltages into the electrical system, posing a risk of electrical shock or fire.

### Key Points:
- **Unified Grounding System:** All grounds, including those for electrical systems, antennas, and lightning protection, should be bonded together.
- **Avoid Sharp Bends:** Ground wires should have smooth, gradual bends to maintain low impedance.
- **Safety First:** Avoid connections that could introduce lightning energy into sensitive or hazardous areas, such as gas lines or ungrounded electrical systems.