Which statement describes a DC circuit?

A DC (Direct Current) circuit is characterized by the fact that the current flows in one direction only. This consistency in direction is what distinguishes DC circuits from AC (Alternating Current) circuits, where the current periodically reverses direction. In a DC circuit, the flow of electric charge is steady and unidirectional, making it ideal for powering devices that require a constant voltage and current, such as batteries and electronic circuits.

This fundamental property of DC circuits ensures predictable and stable operation, which is essential in many applications. Other statements fail to capture the essence of DC circuits; for instance, the indication of current flowing in multiple directions pertains to AC circuits, while the notion of varying resistance and oscillating charges is not applicable to the steady-state nature of a DC circuit. Hence, the correct answer accurately reflects the defining characteristic of a DC circuit.