Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives

Given data : It is given to identify  Phenol when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives, from the given options

Explanation :
When phenol is converted to phenol-2,4-disulphonic acid by the action of concentrated sulphuric acid Conc. $H_{2}S{O}_4$,
Conc. $HN{O}_3$ transforms phenol-2,4-disulphonic acid into 2,4,6-trinitrophenol or picric acid.

The chemical reaction is as follows:
Trinitrotriazidobenzene, also known as TATNB (triazidotrinitrobenzene), and 1,3,5-triazido-2,4,6-trinitrobenzene, is an aromatic high explosive with the chemical formula $C_6{\left(N_3\right)}_3{\left(N{O}_2\right)}_3$. It is made up of a benzene ring with three azido groups ($-N_3$) and three nitro groups ($-N{O}_2$) alternating around the ring.

Hence,  the correct option (B). 2,4,6-Trinitrobenzene.