In a certain double slit experimental arrangement interference fringes of width 1.0 mm each are observed when light of wavelength 5000 Å is used. Keeping the set up unaltered, if the source is replaced by another source of wavelength 6000 Å, the fringe width will be
(A) 0.5 mm
(B) 1.0 mm
(C) 1.2 mm
(D) 1.5 mm