The distance between field lens and eye lens in Ramsden eyepiece is $4 cm$. Then, the distance of the cross-wires from the eye lens is :

Question

$$\begin {array} {1 1} (1)\;1.5 \;cm & \quad (2)\;1.0\;cm \\ (3)\;5.0\;cm & \quad (4)\;5.5\;cm \end {array}$$