A beam of light of $\lambda$ = 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2m away. The distance between first dark fringes on either side of the central bright fringe is :

Question

( A ) 1.2 cm
( B ) 1.2 mm
( C ) 2.4 mm
( D ) 2.4 cm