Which of the following is a measure of the quality of an analog-to-digital converter?

Total harmonic distortion (THD) is a vital performance metric for an analog-to-digital converter. It measures how much unwanted harmonic content the ADC's sampling and quantization processes introduce into the digitized signal. A lower THD indicates a higher quality, more linear ADC. The other options are entirely unrelated to ADC quality metrics. Peak envelope power measures RF transmitter output, power factor applies to AC power circuits, and reciprocal mixing is a receiver issue caused by local oscillator phase noise.