Nitrobenzene on reaction with conc. ${\mathrm{HNO}}_3/$ ${\mathrm{H}}_2{\mathrm{SO}}_4$ at $80-100°\mathrm{C}$ forms which one of the following products?

When ${\mathrm{HNO}}_3$ reacts with ${\mathrm{H}}_2{\mathrm{SO}}_4$ gives nitronium ion as a product. When the nitronium ion reacts with meta position of nitrobenzene, it gives 1,3-dinitrobenzene.

Therefore, option D is correct.