Which of the following group is detected by Barker-Mulliken's test

Write structural formula of the compounds $\mathrm{A}$ to $\mathrm{D}$.

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NO}}_2\underset{\mathrm{conc}. {\mathrm{H}}_2{\mathrm{SO}}_4}{\overset{\mathrm{conc}. {\mathrm{HNO}}_3}{\to }}\mathrm{A}\stackrel{\mathrm{NaSH}}{\to }\mathrm{B}\underset{50\% \mathrm{Ethanol},∆}{\overset{\mathrm{Zn}+{\mathrm{NH}}_4\mathrm{Cl}}{\to }}\mathrm{C}\stackrel{\mathrm{Tollen}\text{'}\mathrm{s} \mathrm{reagent}}{\to }\mathrm{D}$

Predict the major product of the following reaction.

Give balanced chemical equation of reduction of nitrobenzene in neutral medium.

Predict the major product that would be obtained on nitration of the following compound.

The structure of the compound formed, when nitrobenzene is reduced by lithium aluminium hydride$\left({\mathrm{LiAlH}}_4\right)$ is

The product $\mathrm{P}$ in the following reaction is

$\mathrm{Ph}-{\mathrm{NO}}_2 \stackrel{{\mathrm{Na}}_2{\mathrm{AsO}}_3/\mathrm{NaOH}}{\to }\mathrm{P}$

Barker-Mulliken's test can be used for the detection of _____ group.
(A) $-{\mathrm{NH}}_2$    (B) $-{\mathrm{SO}}_4$    (C) $-{\mathrm{NO}}_2$

Enter your correct answer as A, B or C.