Which of the following compounds is not aromatic?

Aromaticity of a compound can be decided by Huckel's rule. In cyclopentadienyl cation (b), resonance takes place as follows:Hence, is anti-aromatic does not followHuckel's rule as it has conjugated 4π-electron(4nπ,n=1) system. Rest of the species are aromatic as each of them belongs to 6π-electron [(4n+2)π, n = 1] system.