*Question G2C08:
What prosign is sent to indicate the end of a formal message when using CW?*  

*Correct Answer is  C: AR*  

### AI Response: (may contain errors)  

In Morse code (CW), prosigns are special sequences of characters that convey specific procedural signals. Understanding these prosigns is essential for effective communication in amateur radio.

### Explanation:

1. **Correct Answer: C: AR**
   - The prosign **AR** is used to indicate the end of a formal message. It signals to the receiving station that the message is complete and no more information will follow. This helps in distinguishing the end of the message from any subsequent communication.

2. **Why the Other Choices are Incorrect:**
   - **A: SK**
     - The prosign **SK** is used to indicate the end of a communication session. It means "silent key" or "end of contact," signaling that the operator is signing off and will not be transmitting further.
   - **B: BK**
     - The prosign **BK** is used to break into a conversation or to indicate a break in transmission. It is often used to quickly hand over the transmission to the other operator without the formalities of ending a message.
   - **D: KN**
     - The prosign **KN** is used to indicate that the transmission is directed to a specific station. It means "go ahead, specific station," and is used when you want only a particular station to respond.

### Summary:
- **AR**: End of message
- **SK**: End of contact
- **BK**: Break in transmission
- **KN**: Go ahead, specific station

Understanding these prosigns helps ensure clear and efficient communication in CW operations.