Water waves with wavelength $\lambda$ are produced in a ripple tank. As they go through a narrow gap of width $d$ ($d$ is greater than $\lambda$), the waves are diffracted. Which combination of gap width and wavelength would produce the greatest reduction in the amount of diffraction?
- Agap width $\frac{1}{2}d$, wavelength $\frac{1}{2}\lambda$
- Bgap width $\frac{1}{2}d$, wavelength $2\lambda$
- Cgap width $2d$, wavelength $\frac{1}{2}\lambda$
- Dgap width $2d$, wavelength $2\lambda$