A monochromatic laser beam in air with index of refraction \(n \approx 1.0\) passes through a single slit of width \(a\), forming a diffraction pattern on a screen located a distance \(L\) away. The width of the central diffraction maximum on the screen is measured to be \(W\). The entire apparatus—laser, slit, and screen—is then completely submerged in a tank filled with water with index of refraction \(n = 1.33\). Which of the following correctly describes what happens to the width \(W\) of the central diffraction maximum and provides the correct physical justification?