Two wave sources vibrate in phase. Each source emits a wave with wavelength $\lambda$. At point X, the two waves arriving from the sources have a phase difference of $90^{\circ}$. What is one possible difference between the distances from the two wave sources to point X?
- A$\frac{\lambda}{8}$
- B$\frac{\lambda}{4}$
- C$\frac{\lambda}{2}$
- D$\lambda$