Which of the following describes an analog signal?

• A. Discrete values
• B. Fixed steps between values
• C. Continuous variation of the signal is possible
• D. Levels are determined by bits

Answer: (C)

An analog signal is characterized by continuous variation in time and amplitude, meaning it can take an unlimited number of values within its range and smoothly change instead of jumping between levels. This makes the statement about continuous variation the best description of an analog signal.

Discretizing a signal means it only has specific, separate values, which is a hallmark of digital signals or sampled data. Fixed steps between values describe a staircase or quantized signal, also not truly continuous. Levels determined by bits point to digital encoding, where a finite set of levels is defined by the number of bits.