A to 2, B to 3, C to 1, and D to 4. Happy to help! ☺
I believe the answer is A
<span>The answer is timbre. Timbre is a feature of the sound, which is a wave. Other features of sound are pitch (related with frequency) and loudness. Timbre is the feature of sound that permit ear to distinguish sounds with the same frequency and loudness.</span>
