Which port is likely to be used for sound input from a DVD player sitting beside the computer?

standard RCA cable harness (the red white and yellow cables) are likely to be used for a DVD Player, you could also use a tv tuner and coaxile cable if you use and RF modulator. ---- Actually this question is referring to question 20, Chapter 10, Guide to Managing & Maintaining Your PC, Sixth Edition by Jean Andrews. The answer is referenced on p438. The answer is the blue port(Line-in) which is also used for Music Synthesizers, a microphone, CD Player or other external device producing sound.