Which type of impedance remains consistent regardless of frequency?

Resistance is defined as the opposition to the flow of electric current, and its characteristic remains constant across different frequencies. This is because resistance is not dependent on the frequency of the applied signal; instead, it is solely determined by the physical properties and configuration of the material through which the current flows.

In contrast, reactive impedance changes with frequency. Reactive components, such as inductors and capacitors, exhibit behaviors that vary depending on the frequency of the applied signal. Inductors increase their impedance with frequency, while capacitors decrease it. Admittance, which is the measure of how easily a circuit or device allows current to flow, also incorporates frequency-dependent components, particularly if reactance is involved. Lastly, capacitance, which specifically refers to a capacitor's ability to store charge, is similarly frequency-dependent, as it changes the way capacitors behave in AC circuits.

Thus, resistance is unique in its consistent value across all frequencies, making it the correct answer to the question regarding impedance that remains unchanged regardless of frequency.