Which statement is true regarding inductors in circuits?

Inductors are components in electrical circuits that store energy in a magnetic field when electrical current passes through them. One of their key characteristics is their ability to oppose changes in current. When there is a rapid change in current through an inductor, it generates a back electromotive force (EMF) that resists this change, effectively stabilizing the current flow. This characteristic is vital in many applications, particularly in smoothing out current fluctuations in power supplies and in filters within AC circuits.

In the context of the other options, inductors can indeed work with AC currents, but they are also relevant in DC applications during switching events. They are commonly used in various power applications, contradicting the claim of option B. Lastly, while inductors can influence voltage levels in a circuit, they do not inherently decrease voltage; rather, they may cause a phase shift or react to changes in current, but the specific effect on voltage can vary based on the circuit design and conditions. Thus, option C accurately describes the behavior of inductors in circuits.