The total number of aromatic compounds/species from the following is

Step-by-step solution

A species is aromatic if it is cyclic, planar, fully conjugated (continuous cyclic overlap of p -orbitals) and contains (4n + 2) , electrons (Huckel's rule). Let us analyse each species. 1,4 -Benzoquinone: The six-membered ring has only 4 electrons (from the two C=C bonds); the two C=O groups are cross-conjugated and do not contribute to a continuous (4n + 2) , ring system. Hence, it is non-aromatic. Tropylium cation: A planar, cyclic, fully conjugated seven-membered system with three C=C bonds and a positive charg