Assuming human pupil to have a radius of $0.25\;cm$ and a comfortable viewing distance of $25\;cm$ , the minimum separation between two objects that human eye can resolve at 500 nm wavelength is :

Question

$\begin{array}{1 1} 100\;\mu m \\ 300\;\mu m \\ 1 \;\mu \\ 30\; \mu m \end{array} $