Clar has the answer! Clar's π-sextets justify the reason why the linked system of [o-COSAN]⁻ and benzenoid drives to extrusion in the case of naphthalene or anthracene, but not for benzene, pyrene or perylene. Benzene and pyrene can be synthetically linked to [o-COSAN]⁻ keeping their aromaticity. In contrast, naphthalene and anthracene are extruded in the same reaction. We have proven that extrusion is only favorable if the number of Clar's π-sextets remains constant. Thus, Clar has the answer to whether an attached polycyclic aromatic hydrocarbon to [o-COSAN]⁻ is extruded or not.