b
Benzene has molecular formula \(\mathrm{C}_{6} \mathrm{H}_{6}\) that is there is the presence of a double bond in between alternate carbon atoms and each carbon is attached to two carbon atoms by means of a single bond and a double bond and a hydrogen atom by a single bond.

So there are a total of 12 sigma bonds and 3 pi bonds in benzene. The carbon atoms are bonded through \(\mathrm{sp}^{2}-\mathrm{Sp}^{2}\) overlap while six \(\mathrm{C}-\mathrm{H}\) bond is formed by \(\mathrm{sp}^{2}-\mathrm{s}\) sigma bond.

Thus there is \(6 \mathrm{sp}^{2}-\mathrm{s}\) sigma bond.