The number of $sp^2-s$ sigma bonds in benzene are

The number of $\sigma$ and $\pi$ bonds in a molecule of benzene is

The product of the following reaction is:

In the following sequence of reactions,the maximum number of atoms present in molecule $C$ in one plane is:
$A$ $\xrightarrow[Cu \text{ tube}]{\text{Red hot}} B$ $\xrightarrow[\text{Anhydrous } AlCl_3]{CH_3Cl (1 \text{ eq})} C$
($A$ is the lowest molecular weight alkyne)

Which of the following compounds has two different $C-C$ bond lengths?

The electrophilic aromatic substitution proceeds through a