A monochromatic plane wave moving with speed $c$ and wavelength $\lambda$ is diffracted by a small aperture. The diagram shows a succession of wavefronts. How long will it take for some part of the wavefront XY to reach point P?
- A$\frac{3\lambda}{2c}$
- B$\frac{2\lambda}{c}$
- C$\frac{3\lambda}{c}$
- D$\frac{4\lambda}{c}$