A two-slit experiment with red light produces a set of bright fringes.
(a) Will the spacing between the fringes increase, decrease, or stay the same if the color of the light is changed to blue?
(b) Choose the best explanation from among the following:
I. The spacing between the fringes will increase because blue light has a greater frequency than red light.
II. The fringe spacing decreases because blue light has a shorter wavelength than red light.
III. Only the wave property of light is important in producing the fringes, not the color of the light. Therefore the spacing stays the same.