*Question G2C09:
What does the Q signal “QSL” mean?*  

*Correct Answer is  C: I have received and understood*  

### AI Response: (may contain errors)  

The Q signal "QSL" is part of a standardized set of three-letter codes used in amateur radio to convey specific messages quickly and efficiently. Here's a breakdown of the correct answer and why the other choices are incorrect:

1. **Correct Answer: C: I have received and understood**
   - "QSL" is used to confirm receipt of a message or information. It essentially means "I acknowledge receipt" or "I have received and understood your transmission." This is a common practice in radio communications to ensure that messages are correctly received and acknowledged.

2. **Why the other choices are incorrect:**
   - **A: Send slower**  
     This is incorrect because the Q signal for "send slower" is "QRS." "QRS" is used when a station requests the other party to reduce their sending speed, typically in Morse code communications.
   
   - **B: We have already confirmed the contact**  
     This is incorrect because "QSL" does not imply a prior confirmation. Instead, it is used to confirm the current receipt of information. The concept of confirming a contact is more related to exchanging QSL cards, which are physical or electronic cards used to confirm a contact between two amateur radio stations.
   
   - **D: We have worked before**  
     This is incorrect because the Q signal for "we have worked before" is "QSO." "QSO" refers to a contact or conversation between two amateur radio stations, and it can imply that the stations have communicated previously.

Understanding Q signals is crucial for efficient communication in amateur radio, as they help convey complex messages with simple codes.