Which bands are MF/HF radio systems mentioned as using in the material?

• A. 8 MHz and 22 MHz
• B. 6 MHz and 18 MHz
• C. 3 MHz and 12 MHz
• D. 10 MHz and 25 MHz

Answer: (A)

MF/HF radio systems operate across a broad portion of the spectrum outside VHF, roughly from about 2 to 30 MHz, and rely on ionospheric propagation to reach distant stations. The material uses 8 MHz and 22 MHz as examples of bands that these MF/HF systems operate on, showing real frequencies within that range that are used for long‑range maritime communication. The lower end around 8 MHz and the higher end around 22 MHz illustrate how different parts of the HF spectrum can be used under varying ionospheric conditions to achieve global reach. Other frequency pairs don’t align with the bands described in the material or aren’t cited as typical MF/HF examples.