Correct Answer - C
Fe(Z=26): `[Ar]^(18)4s^(2)3d^(6)`
Fe after pairing up of six 3d-electrons in three d-orbitals, undergo `d^(2)sp^(3)`-hybridisation. One of the six hybridized orbitals so obtained contains a lons pair (from 4s-orbital). Thus shape of `Fe(CO)_(5)` is square pyuare pyramidal.
