Which are prisms among the following ?

We know that a prism is a polyhedron, two of whose faces are congruent polygons in parallel planes and whose other faces are parallelograms. Therefore,

**(i)** A nail is not a prism.

**(ii)** An unsharpened pencil is a prism.

**(iii)** A table weight is not a prism.

**(iv)** A box is a prism.