When aniline is heated with conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ at 455-475K, it forms          

To find the product when aniline is heated with conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ at $455-475 \mathrm{K}$Aniline on reaction with concentrated $H_{2}S{O}_4$forms aniline hydrogen sulfate followed by heating at 453-473K it undergoes rearrangement to give p-amino benzene sulphonic acid                             

Hence the correct option is C.