A yellow coloured dye is obtained by the reaction of $\mathrm{X}$ with benzene diazonium chloride. The reactant $\mathrm{X}$ is

The final product $\mathrm{R}$ is

Consider the following reaction:

The product $\mathrm{\text{'}}{\mathrm{X}}^{\mathrm{\text{'}}}$ is used:

The major product of the following reaction is

In a set of reactions $\mathrm{p}-$ nitrotoluene yielded a product $\mathrm{E}$



Product $\mathrm{E}$ would be:

The reaction,

 is called