*Question T0A06:
What is a good way to guard against electrical shock at your station?*  

*Correct Answer is  D: All these choices are correct*  

### AI Response: (may contain errors)  

To guard against electrical shock at your station, the correct answer is:

**D: All these choices are correct.**

### Explanation of the Correct Answer:
1. **Three-wire cords and plugs**:  
   - Using three-wire cords and plugs ensures that there is a ground connection. This provides a path for fault current to flow safely to the ground, reducing the risk of shock.
  
2. **Common safety ground**:  
   - Connecting all AC powered equipment to a common safety ground helps to ensure that all equipment is at the same electrical potential. This minimizes the risk of shock from differences in voltage between devices.

3. **Mechanical interlocks in high-voltage circuits**:  
   - Installing mechanical interlocks prevents accidental access to high-voltage circuits while they are energized. This is a critical safety feature that protects users from exposure to dangerous voltages.

### Why Other Choices Are Incorrect:
- **A: Use three-wire cords and plugs for all AC powered equipment**:  
  - While this is a good practice, it alone does not cover all safety measures needed to prevent electrical shock.

- **B: Connect all AC powered station equipment to a common safety ground**:  
  - This is also a good practice, but it does not encompass the full range of safety measures necessary for comprehensive protection.

- **C: Install mechanical interlocks in high-voltage circuits**:  
  - This is an important safety feature, but it does not address the risks associated with all AC powered equipment.

### Summary:
All the choices provided contribute to a safer operating environment in an amateur radio station. Therefore, the best answer is that all these choices are correct, as they collectively enhance safety against electrical shock. 

### Useful Rules of Thumb:
- Always use equipment with proper grounding.
- Regularly check grounding connections for integrity.
- Ensure that high-voltage areas are clearly marked and secured.