*Question G2D09:
Which of the following is required when participating in a contest on HF frequencies?*  

*Correct Answer is  C: Identify your station according to normal FCC regulations*  

### AI Response: (may contain errors)  

The correct answer to the question is **C: Identify your station according to normal FCC regulations**. Here's why this answer is correct and why the others are not:

### Explanation of the Correct Answer (C)
- **Identification Requirement**: According to FCC regulations, all amateur radio operators must identify their station with their call sign at the end of each communication and at least every 10 minutes during a conversation. This rule applies regardless of whether you are participating in a contest or not. 

### Explanation of the Incorrect Answers
- **A: Submit a log to the contest sponsor**  
  - While many contests do require participants to submit logs, this is not a universal requirement for all HF contests. Some informal contests may not require log submissions, making this choice not universally correct.

- **B: Send a QSL card to the stations worked, or QSL via Logbook of The World**  
  - Sending QSL cards is a common practice but is not mandatory for contest participation. Contest rules may vary, and some operators may choose not to send QSLs at all, making this choice incorrect.

- **D: All these choices are correct**  
  - Since A and B are not universally required, this choice cannot be correct. The only requirement that applies to all HF contest participants is the identification of the station.

### Summary
In summary, while submitting logs and sending QSL cards can enhance your contest experience and are often encouraged, the only absolute requirement when participating in a contest on HF frequencies is to identify your station according to FCC regulations. Always remember to follow the rules for identification to stay compliant with amateur radio regulations.