Explanation: Transmitters generate energy at the fundamental operating frequency, but imperfections in the circuit can also produce signals at integer multiples of this frequency, known as harmonics. **A) To prevent interference from occurring with other radio services:** If these harmonics are strong enough, they can radiate significant power on frequencies far removed from the intended operating band. These frequencies often fall within bands allocated to other amateur operators, commercial services, public safety, or even broadcast television, causing severe interference. **B) To restrict the bandwidth of the particular station to the legal limits:** Harmonics are a type of spurious emission. FCC regulations (like Part 97.307 for amateur radio) mandate that transmitters must suppress these unwanted emissions to a certain level (e.g., 43 dB below the fundamental power). This ensures the station's *entire* radiated spectrum, including any unwanted emissions, complies with spectral purity standards, preventing it from radiating energy outside its intended operating frequency and thus staying within its "legal limits" for a clean transmission. Since suppressing harmonics achieves both preventing interference and complying with regulatory limits on spectral purity, both A and B are correct.