Correct Option: B
From a single cube of dimension 5 cm, we can create 125 cubes of 1cm each.
All the faces of the cube are painted. Remove 1cm dimension from all the faces of the cube. Whatever left portion will contain cubes which are not painted on either side. That way a cube with a dimension of 5cm reduces to a dimension of 3 cm, 3 cube equals 27. Thus you can create 27 cubes which are not painted on either side.