A stationary wave is formed by two loudspeakers that emit sound at the same frequency. As a microphone is shifted between X and Y, which are $1.5\,\text{m}$ apart, six nodes and seven antinodes are observed. What is the wavelength of the sound?
- A$0.50\,\text{m}$
- B$0.43\,\text{m}$
- C$0.25\,\text{m}$
- D$0.21\,\text{m}$