Which of the following units can be used to represent signal level values?

Signal level values can indeed be represented using different units, each serving specific contexts and applications in signal processing and communication systems.

Millivolt (mV) is a direct measurement of voltage level, which is crucial for assessing the strength of electrical signals in various systems. Decibel millivolt (dBmV) is a logarithmic scale that expresses signal levels relative to one millivolt, allowing easier comparisons and analyses of signal strengths across different systems. This unit is particularly useful in communications as it reflects how different signal levels behave relative to a fixed reference.

Microwatt (µW) represents power rather than voltage, but it is still applicable in scenarios where power levels of signals are being evaluated, especially in wireless communications. Each of these units can provide critical insight depending on whether one is assessing voltage or power levels in a system, illustrating how signal strength can be represented in different formats.

By including all three units—millivolt, decibel millivolt, and microwatt—the correct answer captures the broader spectrum of measurements used in the field. Thus, this option reflects the complex nature of signal representation in electronic and communication applications.