Which process would be used to achieve a stable DC output?

In electrical engineering, achieving a stable DC output from an AC source is primarily accomplished through the process of rectification. This process involves converting alternating current (AC), which periodically reverses direction, into direct current (DC) that flows in a single direction.

Rectification is typically done using components like diodes, which allow current to flow only in one direction while blocking it in the opposite direction. This conversion creates a pulsed DC output that can then be further smoothed out to provide a steady DC voltage using filtering techniques.

While inductance and capacitance play important roles in various electrical circuits—inductance storing energy in a magnetic field and capacitance storing energy in an electric field—neither directly converts AC to DC. Inductance can help in high-frequency applications and reducing ripple in circuits, while capacitance is essential in smoothing out the output after rectification.

Frequency modulation is unrelated to the conversion of AC to DC and pertains to the technique of varying a carrier signal’s frequency to convey information.

Thus, rectification is the fundamental process to create a stable DC output from an AC source, making it the correct answer.