Which one of the following is not a characteristic of benzene?

Explanation

The delocalised ring of six pi electrons makes benzene unusually stable, so it resists addition and reacts only under forcing conditions, preferring substitution which preserves the aromatic system. Aromaticity, stability and obedience to Huckel's 4n plus 2 rule are all genuine features. Expecting benzene to behave like a reactive alkene is precisely the misconception this question targets.