47. Coherent light with wavelength 0.40 μm passes through two very narrow slits. The distance between these two slits is 0.20 mm. The interference pattern is shown on a screen 5.0 m from the slits. What is the width of the central interference maximum? (A) 7.5 mm (B) 5.0 mm (C) 20 mm (D) 10 mm (E) 2.5 mm