After the quantization step, the signal is best described as which?

After the quantization step, the signal is best described as which?

• A. A Discrete-time, discrete amplitude signal
• B. B Discrete-time, continuous amplitude signal
• C. C Continuous-time, discrete amplitude signal
• D. D Digital output signal

Answer: (A)

Quantization turns the signal’s amplitudes into a finite set of levels, so the amplitude becomes discrete. At the same time, sampling (which usually happens before quantization) already makes the time axis discrete. Put together, after quantization you have a signal that is discrete in time and discrete in amplitude—a discrete-time, discrete-amplitude signal. The other descriptions don’t fit: continuous amplitude would mean quantization hasn’t happened, continuous time would mean sampling hasn’t occurred, and “digital output” is too vague and doesn’t specify the discrete-amplitude aspect.