Of Hückel's Requirements for Aromatic Character,only This One Is Waived $\pi$

Of Hückel's requirements for aromatic character,only this one is waived in the case of certain compounds considered to be aromatic.

A) The ring system must be planar.
B) The system must be monocyclic.
C) There must be (4n + 2) $\pi$ electrons.
D) The Hückel number of electrons must be completely delocalized.
E) None.All of these rules must apply in every case.