During which state does direct current flow?

Direct current (DC) flows in only one direction, which is a defining characteristic of this type of electrical current. This unidirectional flow allows for a consistent and stable voltage, making DC ideal for powering devices and batteries where a constant and steady energy supply is necessary.

In contrast, the other options describe characteristics not associated with direct current. Fluctuation and rapid alternation are more applicable to alternating current (AC), where the current changes direction periodically. The idea of flowing indefinitely is not specific to how current operates under different circuits, as all current requires a complete path to flow and does not inherently flow indefinitely without consideration of the circuit's configuration. Therefore, the nature of direct current as moving steadily in one direction is crucial for understanding its applications and behaviors in practical scenarios.