*Question T8C10:
What is required before using the EchoLink system?*  

*Correct Answer is  C: Register your call sign and provide proof of license*  

### AI Response: (may contain errors)  

To use the EchoLink system, the correct requirement is to register your call sign and provide proof of license. Here’s a breakdown of why this is the case and why the other options are incorrect:

### Correct Answer: C - Register your call sign and provide proof of license

- **Explanation**: EchoLink is a system that allows licensed amateur radio operators to connect to each other over the internet. To use EchoLink, you must have a valid amateur radio license, which is verified by registering your call sign with the EchoLink system. This ensures that only licensed operators can access the system, maintaining compliance with amateur radio regulations.

### Why the Other Choices are Incorrect:

- **A: Complete the required EchoLink training**  
  - **Explanation**: While training and understanding how to use EchoLink is beneficial, there is no formal training requirement mandated by the system. The primary requirement is to have a valid license and registered call sign.

- **B: Purchase a license to use the EchoLink software**  
  - **Explanation**: EchoLink software is free to download and use for licensed amateur radio operators. There is no cost associated with obtaining a license specifically for using the software, as long as you hold a valid amateur radio license.

- **D: All these choices are correct**  
  - **Explanation**: Since options A and B are incorrect, this choice cannot be correct. The only requirement is to register your call sign and provide proof of your amateur radio license.

### Summary

To use EchoLink, ensure you:
- Have a valid amateur radio license.
- Register your call sign with the EchoLink system.

This maintains the integrity of the amateur radio community and ensures compliance with regulations.