Explanation: Op-amp (active) audio filters are powered circuits designed to amplify signals, meaning they can provide gain or at least avoid the signal attenuation common in filters. Conversely, passive LC filters, composed only of inductors and capacitors, always introduce some degree of insertion loss because they have no power source to boost the signal and inherently dissipate some energy. This ability to provide gain is a significant advantage, allowing for clearer signals, easier impedance matching, and the cascading of multiple filter stages without excessive signal degradation. Regarding the other options: A) Both op-amps and LC components can be affected by temperature and vibration, though careful design can mitigate this for either. It's not a primary distinguishing advantage for op-amps. B) This is an economic statement about manufacturing trends, not a technical advantage of the filter type itself. C) While true, the widespread availability of op-amps doesn't highlight a *performance* advantage of an op-amp filter over a passive LC filter concerning signal characteristics.