Characteristics of a Digital Signal
A digital signal is a representation of information using discrete states or values, typically represented as binary digits (0s and 1s). It has several characteristics that distinguish it from analog signals.

Quantized Values
One of the main characteristics of a digital signal is that it takes quantized values. This means that the signal can only have specific discrete values, rather than being continuous. In other words, a digital signal can only be in one of a finite number of states at any given time. These states are typically represented by binary digits, where each digit can be either 0 or 1. For example, a digital signal may have quantized values of 0, 1, 2, 3, etc., depending on the number of bits used to represent it.

Discrete Waveform
Unlike analog signals, which have continuous waveforms that can take any value within a range, digital signals have discrete waveforms. This means that the waveform of a digital signal is made up of a series of discrete values or levels. Each level corresponds to a specific quantized value. For example, a digital signal with two levels (0 and 1) would have a waveform that switches between these two levels.

Number of Signals Produced by N Bits
The maximum number of signals that can be produced by N bits is given by 2^N. This is because each bit can have two possible states (0 or 1), and there are N bits in total. However, the correct option in the given question states that the maximum number of signals is 2N-1. This is incorrect, as it does not account for the fact that all possible combinations of N bits can be used to represent different signals.

No Loss of Value
Converting an analog signal to a digital signal involves a process called quantization, where the continuous values of the analog signal are approximated by a series of discrete values. While there may be some loss of precision during this conversion process, once the analog signal is represented in digital form, there is no further loss of value. This is because the digital signal is represented by a fixed number of bits, and each bit retains its value until it is changed.

In summary, the correct characteristic of a digital signal is that it takes quantized values. The waveform of a digital signal is discrete, and the maximum number of signals that can be produced by N bits is 2^N. Additionally, once an analog signal is converted to a digital signal, there is no loss of value.

Ya it's A .because, as name indicates digital it have specific values like 2,3,4 it will round of your signal values i.e., if the signal amp value at a point is 2.3 it takes 2. so that is quantisation process.