*Question G0A12:
[1.1307(1)(b)(3)(i)(A)] What stations are subject to the FCC rules on RF exposure?*  

*Correct Answer is  D: All stations with a time-averaged transmission of more than one milliwatt*  

### AI Response: (may contain errors)  

The correct answer to the question about which stations are subject to the FCC rules on RF exposure is:

**D: All stations with a time-averaged transmission of more than one milliwatt.**

### Explanation of the Correct Answer:
- The FCC regulations on RF exposure apply to all radio frequency (RF) transmitting stations, regardless of their type (commercial or amateur), as long as they exceed a certain power threshold.
- The threshold is set at a time-averaged transmission of more than one milliwatt (1 mW). This means that any station transmitting at or above this power level must comply with the RF exposure guidelines to ensure safety for both operators and the public.

### Why the Other Choices are Incorrect:
- **A: All commercial stations; amateur radio stations are exempt.**
  - This is incorrect because amateur radio stations are not exempt from RF exposure rules. All stations, including amateur ones, must adhere to these regulations if they exceed the specified power level.

- **B: Only stations with antennas lower than one wavelength above the ground.**
  - This choice is misleading. The height of the antenna does not determine whether RF exposure rules apply. The rules are based on the power output, not the antenna height.

- **C: Only stations transmitting more than 500 watts PEP.**
  - This is incorrect because the RF exposure rules apply to all stations transmitting more than 1 mW, not just those exceeding 500 watts. The 500 watts figure is not relevant to the RF exposure regulations.

### Useful Rules of Thumb:
- **RF Exposure Threshold:** 
  - The key threshold for RF exposure compliance is 1 mW. Stations operating above this level must evaluate their RF exposure to ensure it meets FCC guidelines.
  
- **General Safety Practices:**
  - Always maintain a safe distance from antennas when transmitting, especially at higher power levels.
  - Use RF exposure calculators or guidelines provided by the FCC to assess compliance based on your specific setup.

Understanding these points will help you grasp the importance of RF exposure regulations and their applicability to all transmitting stations.