The correct answer is B: A small amount of noise added to the input signal to reduce quantization noise. Dither with respect to analog-to-digital converters is a small amount of noise added to the input signal to reduce quantization noise. Dithering improves ADC performance by randomizing quantization errors. Without dither, quantization errors can create patterns and distortion. By adding a small amount of random noise (dither) before quantization, the quantization errors become randomized rather than correlated with the signal. This reduces harmonic distortion and improves the effective resolution of the ADC. The dither noise is typically much smaller than the signal and is often filtered out after conversion. Dithering is a common technique in high-quality audio and measurement ADCs.