Aniline on treatment with bromine water yields a white precipitate of

In the reaction sequence identify the functional group present in $\mathrm{A},\mathrm{B},\mathrm{C}$ :

$\mathrm{A} \stackrel{\mathrm{Sn}/\mathrm{HCl}}{\to } \mathrm{B} \underset{0-5°\mathrm{C}}{\overset{{\mathrm{HNO}}_2}{\to }} \mathrm{C} \stackrel{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}}{\to } {\mathrm{C}}_6{\mathrm{H}}_6$

Arrange in decreasing order of basic strength :

(I)	(II)	(III)	(IV)