Assertion: Thiophene is present in commercial benzene as the impurity can be removed by shaking the mixture with cold concentrated ${\mathrm{H}}_2{\mathrm{SO}}_4$.
Reason: Thiophene is a heterocyclic aromatic compound.

The major product of the following reaction is:

The correct IUPAC name of the following compound is:

In the following reactions

$\mathrm{X}$ and $\mathrm{Y}$, respectively, are:

Among the following, the reaction that proceeds through an electrophilic substitution, is:

The major product obtained in the given reaction is:

The compounds $\mathrm{A}$ and $\mathrm{B}$ in the following reaction are, respectively:

The correct name of the following polymer is: