We listen to programs of different stations by turning the knob of the radio due to resonance (Option A). Radios operate by tuning circuits, which consist of inductors and capacitors that can be adjusted to resonate at specific frequencies. When we turn the knob, we are changing the inductance or capacitance, thereby altering the resonant frequency of the circuit. This adjustment allows the radio to select and amplify the electromagnetic waves from a particular station’s broadcast frequency while ignoring others. Resonance occurs when the circuit’s natural frequency matches the frequency of the incoming radio signal, resulting in maximum energy transfer and a clear signal reception. This principle is fundamental in radio technology, as it enables the selective tuning to different broadcast signals, ensuring that we can listen to various stations by simply adjusting the tuning knob to match the desired frequency.