Reaction of ${\mathrm{SO}}_3$ is easier in:

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

 The major product of the following reaction is:

The major product obtained in the given reaction is:

In the following reaction sequence the major products $\mathrm{A}$ and $\mathrm{B}$ are :

In the following reactions

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

The major product of the following reaction is: