The main scale of vernier callipers reads in millimetre and its vernier is divided into `10` divisions which coincide with `9` divisions of the main scale. When there is nothing between the jaws of the vernier callipers, the `7th` divisions of vernier scale coincides with a division of main scale and in this case zero of vernier scale is lying on right side of the zero of main scale. When a cylinder is tigthly placed along its length between the jaws, the zero of the vernier scale is slightly left to be `3.1 cm` and `4th VSD` coincides with a scale division. The length of the cylinder is
A. `3.2 cm`
B. `3.07 cm`
C. `3.21 cm`
D. `2.99 cm`
