The statement which are correct regarding benzene are : (i) It has $12 \sigma$ and $3 \pi$ bonds. (ii) There is delocalisation of $\pi$ - electrons. (c) $C-C$ bond distance is $1.39 A^{\circ}$ . (d) $C-C$ bond distance is $1.39 A^{\circ}$ and $1.54\;A^{\circ}$ alternatively .