Monochromatic light of wavelength $5000\;A^{\circ}$ is used in Y.D.S.E with slit- width $d= 1 mm$distance between screen and slits $D=1\;m$ Find the distance of 1000 th maxima

Question

$(a)\;\frac{1}{\sqrt 2} \\ (b)\;\frac{1}{\sqrt 3} \\ (c)\;3 m \\ (d)\;\frac{1}{2 \sqrt 2}\;m$