Attacking species in nitration of benzene in presence of fuming HNO₃ is

In the reduction of nitrobenzene, which of the following is the intermediate?

In the above sequence, Y can be

Tertiary nitro compounds do not tautomerise because

Nitrobenzene on further excessive nitration gives

Tautomerism will be exhibited by

Consider the following reaction
What is Y?

The major product (70% to 8%) of the reaction between m-dinitrobenzene with NH₄HS is

The reagent that reacts with nitromethane to form  methylhydroxylamine is