What are the FCC rules regarding power levels used in the amateur bands?

The FCC rules governing amateur radio operation emphasize that operators should use the minimum power necessary to achieve effective communication. This principle helps promote responsible operation of the amateur bands and is intended to reduce interference with other communications. By using only the power necessary for a contact, operators can limit their signal's potential to cause disruption to other users of the spectrum.

Operating at lower power levels whenever possible is also beneficial for the overall efficiency of communication. It leads not only to more courteous operating practices but also helps preserve the limited resources of the radio spectrum, which can become congested. The intent behind this regulation aligns with the broader amateur radio community's goals of sharing the airwaves and minimizing interference, as well as sustaining the hobby for future operators.

In contrast, the other options suggest practices that either promote maximum power usage or indicate limits that do not apply universally across all amateur frequencies. Only option D aligns with the ideal principle of responsible and efficient amateur radio operation.