The diagram illustrates an experiment for creating a stationary wave in an air column. A tuning fork above the column vibrates, generating a sound wave. The length of the air column may be changed by adjusting the amount of water in the tube. The tube is filled and then the water is allowed to drain from it. The first two stationary waves are produced when the air column lengths are $0.14\,\text{m}$ and $0.42\,\text{m}$. What wavelength does the sound wave have?
- A$0.14\,\text{m}$
- B$0.28\,\text{m}$
- C$0.42\,\text{m}$
- D$0.56\,\text{m}$