A screen is placed 2 m away from a narrow slit. If the first minimum lies 5 mm from either side ofthe centre maxima, when plane waves of wavelength `5 xx 10^-7m` are used, the slit width is

Options

A. `4.8 xx 10^-4 m`
B. `2 xx 10^-4 m`
C. `5 xx 10^-4 m`
D. `2.4 xx 10^-4 m`.