German chemist and physicist Erich Hückel proposed a theory to help determine if a planar ring molecule would have aromatic properties. His rule states that if a cyclic, planar molecule has 4n+2 π electrons, it is considered aromatic. This rule would come to be known as Hückel's Rule

In the above molecule,There is an sp3 hybridized carbon in the ring.Hence, it is not involved in conjugation. As delocalization of πelectrons is not there throughout the ring.It is not an aromatic species.
It does not follow Huckel's rule.
But in the other options the species given that is
,
and
are aromatic as they obey Huckel's rule



