In Young's experiment, two coherent sources are placed 0.90 mm apart and fringe are observed one metre away. If it produces second dark fringe at a distance of 1 mm from central fringe, the wavelength of monochromatic light is used would be
(a) 60 x 10-4 cm
(b) 10 x 10-4 cm
(c) 10 x 10-5 cm
(d) 6 x 10-5 cm