Question 1 /When you listen to a guitar duet and constantly hear unpleasant sounds, which of following would best explain the problem? (A) One or more of the guitars is out of tune.
(B) The guitars are tuned correctly.
(C) The guitars are being held incorrectly.
(D) The guitarists are playing softly.

(A) One or more of the guitars is out of tune.
An instrument being out of tune is a common cause of unpleasant sounds coming from it.
Correct tuning wouldn’t be the cause of an unpleasant sound; quite the contrary would be the case (see above).
Incorrect posture certainly wouldn’t help the performance, but it wouldn’t cause constant unpleasant noise.
The guitarists playing softly would cause the noise to be quiet, not constantly unpleasant.