Technician exam question T3B07

WhyAmateur radio bands are identified by their approximate wavelength in meters, in addition to frequency. Amateur bands are commonly identified by their approximate wavelength in meters, "2 meters," "70 centimeters," and so on, alongside their frequency range, a naming convention that predates precise frequency readouts and is still the everyday shorthand hams use, answer A. Traditional letter/number designators (B, used more in military/government contexts) and channel numbers (C) aren't how amateur bands are identified, so D, which depends on all three, is also wrong.