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

Question

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