*Question E2C01:
What indicator is required to be used by US-licensed operators when operating a station via remote control and the remote transmitter is located in the US?*  

*Correct Answer is  D: No additional indicator is required*  

### AI Response: (may contain errors)  

When operating a station via remote control in the US, the correct answer is that no additional indicator is required. Here’s a breakdown of why this is the case and why the other options are incorrect:

### Correct Answer: D - No additional indicator is required
- **Explanation**: According to FCC regulations, when a US-licensed operator is controlling a remote station located in the US, they do not need to add any special indicators to their call sign. The operator's call sign is sufficient to identify the station, regardless of the location of the remote transmitter.

### Why the Other Choices are Incorrect:
- **A: / followed by the USPS two-letter abbreviation for the state in which the remote station is located**
  - **Reason**: This option suggests that operators must indicate the state of the remote station, which is not required by the FCC. The operator's call sign alone suffices.

- **B: /R# where # is the district of the remote station**
  - **Reason**: This option implies that operators must indicate the district of the remote station. However, the FCC does not mandate this for remote operations, making it unnecessary.

- **C: / followed by the ARRL Section of the remote station**
  - **Reason**: Similar to the previous options, this choice suggests that an additional indicator based on the ARRL Section is needed. The FCC rules do not require this, so it is incorrect.

### Summary
- **Key Point**: When operating a remote station in the US, simply using your call sign is sufficient. No additional indicators are necessary, which simplifies the operation and ensures compliance with FCC regulations. 

This understanding is crucial for the Extra Class exam and for practical operation in amateur radio.