*Question G2A01:
Which mode is most commonly used for voice communications on frequencies of 14 MHz or higher?*  

*Correct Answer is  A: Upper sideband*  

### AI Response: (may contain errors)  

The correct answer to the question is **A: Upper sideband**. 

### Explanation of the Correct Answer:
- **Upper Sideband (USB)** is the most commonly used mode for voice communications on frequencies of 14 MHz or higher, particularly in the amateur radio bands. This is because USB provides better clarity and is less susceptible to interference compared to other modes. It is the standard mode for SSB (Single Sideband) voice communications in these frequency ranges.

### Why the Other Choices are Incorrect:
- **B: Lower Sideband (LSB)**: While LSB is used for voice communications, it is primarily utilized on frequencies below 10 MHz. Above this frequency, USB is preferred.
  
- **C: Suppressed Sideband**: This term is often used interchangeably with SSB, but it does not specify a particular sideband (upper or lower). It is not a commonly used term in practice for voice communications.
  
- **D: Double Sideband (DSB)**: This mode transmits both sidebands and is less efficient than SSB. It is not commonly used for voice communications because it requires more power and bandwidth, making it less practical for amateur radio operators.

### Useful Rules of Thumb:
- For voice communications in amateur radio:
  - Use **USB** for frequencies of 14 MHz and above.
  - Use **LSB** for frequencies below 10 MHz.
  
This distinction helps ensure effective communication and adherence to amateur radio practices.