Which statement describes the action of a capacitor?

The statement that describes the action of a capacitor is that it stores energy. A capacitor is an electrical component that consists of two conductive plates separated by an insulating material known as a dielectric. When a voltage is applied across these plates, an electric field develops, allowing the capacitor to accumulate and store electrical energy in the form of an electric field.

When the capacitor is connected to a circuit, it can discharge this stored energy, providing a short burst of power when needed. This function makes capacitors essential in various applications, such as smoothing out fluctuations in power supplies, timing applications, and energy storage in electronic devices.

While opposing changes in current flow is a characteristic of capacitors due to their nature of charging and discharging over time, the fundamental action highlighted here is the energy storage capability. The other options pertain to different aspects of electrical components, and while they may relate to circuit behavior, they do not precisely define the primary function of a capacitor as effectively as energy storage does.