Which component is used to reduce signal noise in electronic circuits?

The correct choice for reducing signal noise in electronic circuits is the Schmitt trigger. A Schmitt trigger is a type of comparator circuit that provides hysteresis, which means it has two different threshold voltage levels for switching on and off. This property helps clean up noisy signals by ensuring that any small fluctuations or noise in the input signal do not cause false triggering. Instead, the Schmitt trigger stabilizes the output by providing a clear distinction between the high and low states of the signal.

In contrast, while resistors, capacitors, and inductors each play important roles in circuit behavior, they do not specifically focus on reducing noise in the same way a Schmitt trigger does. Resistors can affect the signal's amplitude but do not inherently filter noise. Capacitors can be used for filtering purposes in conjunction with other components, but they do not provide the same hysteresis effect. Inductors filter out high-frequency noise due to their reactive properties, but again, they do not provide the decisive threshold switching that characterizes the Schmitt trigger. Thus, the Schmitt trigger is uniquely suited for noise reduction in digital signals.