The epoxide derived from benzene, 1,2-epoxycyclohexa- 3,5-diene, exists in equilibrium wit...

The epoxide derived from benzene, 1,2-epoxycyclohexa- 3,5-diene, exists in equilibrium with a monocyclic isomer oxepine. Which statement is correct concerning the aromaticity of these two isomers?

A. Both are aromatic.

B. Neither is aromatic.

C. l, 2-Epoxycyclohexa-3,5-diene is aromatic; oxepine is not aromatic.

D. Oxepine is aromatic; l,2-epoxycyclohexa-3,5-diene is not aromatic.