A certain sound contains the following frequencies: 400 Hz, 1600 Hz, and 2400 Hz. Select the best description of this sound.A. This is a pure tone. B. This is a complex tone with a fundamental of 400 Hz, plus some of its overtones. C. This is a complex tone with a vrtual pitch of 800 Hz D. These frequencies are unrelated, so they are probably pure tones from three different sound sources.