A travelling microscope consisting of a compound microscope which slides along a graduated vertical pillar attached to a horizontal base.The main scale is divided into half a millimeter and vernier scale of the microscope is divided into 50 divisions equivalent to 49 main scale division. The least count is

Question

$\begin{array}{1 1}(a)\;0.05cm\\(b)\;0.01cm\\(c)\;0.005cm\\(d)\;0.001cm\end{array}$