Answer: To provide the best sound, a sound card needs to have high-quality digital-to-analog conversion (DAC) capabilities. This is because sound cards are responsible for converting digital audio signals into analog signals that can be played through speakers or headphones. The quality of the DAC determines how accurately the digital audio signal is converted into an analog signal, which directly affects the sound quality. A high-quality DAC will result in a more accurate and faithful representation of the original sound, with minimal distortion or noise. Other factors that can affect the sound quality of a sound card include the number of channels, the sampling rate, and the bit depth, but having a high-quality DAC is crucial for achieving the best sound.