*Question T2B11:
Which Q signal indicates that you are changing frequency?*  

*Correct Answer is  B: QSY*  

### AI Response: (may contain errors)  

The correct answer to the question is **B: QSY**.

### Explanation of the Correct Answer:
- **QSY** is the Q signal that indicates a change of frequency. When you send "QSY," you are informing others that you are moving to a different frequency for communication.

### Explanation of the Incorrect Choices:
- **A: QRU**  
  - This Q signal means "Do you have anything for me?" It is used to inquire if the other station has any messages or information to share, not related to changing frequency.

- **C: QSL**  
  - This signal means "I acknowledge receipt" or "I confirm." It is used to confirm that a message has been received, but it does not indicate a frequency change.

- **D: QRZ**  
  - This Q signal means "Who is calling me?" It is used to ask who is trying to make contact, and it does not pertain to changing frequencies.

### Summary:
- **QSY** = Change frequency  
- **QRU** = Do you have anything for me?  
- **QSL** = I acknowledge receipt  
- **QRZ** = Who is calling me?  

Understanding these Q signals is essential for effective communication in amateur radio and will help you on the Extra Class exam.