Which complex compound obeys 18-electron rule

Which of the following compound obey octet rule :

Which of the following compound obey octet rule :

The complex which does not obey EAN rule is

Which of the following ring compounds obeys Huckel's rule ?

Which of the following ring compounds obeys Huckel's rule ?

18 electron rule: Valence shell of a transition metal consists of nine valence orbitals of (n-1) d, ns and np sub-shells, which can accommodate 18 electrons. When a metal complex has 18 valence electrons, it is said to have achieved the same electronic cofiguration as the noble gas at the end of the period. The rule and its exception are similar to the application of the octet rule of main group elements. The rule is not helpful for complexes of the s-block metals, the lanthanides or actinides. Effective atomic number is the total number of electrons possesed by the central possesed by the central metal atom/ion including the electrons contributed by the ligands. It is obvious that if a central transition metal atom/ion achieves 18 electrons in its valence shell, it attains the nearest noble gas cofiguration, which is known as effective atomic numbr (EAN) rule. [Atomic number :Cr=24, Fe=26, Cu=29, Ni=28, Rh=45] Which of the following does not obey EAN rule or 18 electron rule ?

Sidgwick EAN rule says that complex compound has the tendency to achieve the EAN of 36, 54 and 86 for first, second and third transition series elements. Which of the following complex follows sidgwick EAN rule ?