In Young’s double slit experiment, the distance between slits and the screen is $1.0\; m$ and monochromatic light of $600\; nm$ is being used. A person standing near the slits is looking at the fringe pattern. When the separation between the slits is varied, the interference pattern disappears for a particular distance $d_0$ between the slits. If the angular resolution of the eye is $\large\frac{1^{\circ}}{60}$ the value of $d_0$ is close to

Question

$\begin{array}{1 1}(1) 2\;mm \\ (2) 1\;mm \\ (3) 3\;mm \\ (4) 4\;mm \end{array}$