Which species does not have delocalized electrons?

A.     ${\text{NO}}_3^ -$

B.     ${\text{NO}}_2^ -$

C.     ${{\text{O}}_{\text{3}}}$

D.     ${{\text{C}}_{\text{3}}}{{\text{H}}_{\text{6}}}$

D

One respondent mentioned the fact that there is some debate in the literature in relation to possible sigma delocalization in cyclopropane which is a valid comment and although 63.98% of candidates chose D. ${{\text{C}}_{\text{3}}}{{\text{H}}_{\text{6}}}$ as the correct answer, it is fair to state that a different example might have been selected where there is no evidence of delocalization.