A string of length 0.800m is vibrating at 140 Hz in its second harmonic and producing sound that moves at 340 m/s .
What is true about the frequency and wavelength of this sound?
A. The wavelength of the sound is 2.43 mm.
B. The frequency of the sound is 425 Hz.
C. The wavelength of the sound is 0.800 m.
D. The frequency of the sound is 140 Hz.