Digital signaling is described as:

• A. A signaling method that uses continuous waves.
• B. Series of discrete values, often illustrated by a square wave representing ones and zeros.
• C. A call routing feature.
• D. A device for screen capture.

Answer: (B)

Digital signaling uses discrete levels to encode information, typically two levels representing ones and zeros. When plotted over time, it appears as a square-wave or stepped waveform with clear, abrupt transitions between states. This is different from analog signaling, which relies on continuous changes in amplitude, frequency, or phase to carry information. The other descriptions don’t fit because a continuous-wave description describes analog signaling, a call routing feature isn't about how signals are transmitted, and screen capture is unrelated to signaling methods.