The quantization noise in pulse code modulation (PCM) is mostly affected by which of the following options when the input signal is a random process?

Correct option is C

​$$\text{In Pulse Code Modulation (PCM), when the input signal is a random process, the quantization noise power mainly depends on the quantization step size, which is directly related to the number of quantization levels } L . \\[8pt]\bullet \ \text{Increasing the number of quantization levels } \Rightarrow \text{ smaller step size} \\[4pt]\bullet \ \text{Smaller step size } \Rightarrow \text{ lower quantization noise} \\[10pt]\text{Mathematically, quantization noise power is proportional to:} \\[8pt]\Delta^{2} \propto \left(\frac{1}{L}\right)^{2} \\[10pt]\text{Thus, the number of quantization levels is the dominant factor affecting quantization noise.}$$​​