The reaction mechanism involves nitration followed by hydrolysis:
\[ \text{Bromobenzene} \xrightarrow{\text{Conc. HNO}_3} \text{Bromonitrobenzene (A)} \]
Then:
\[ \text{Bromonitrobenzene (A)} \xrightarrow{\text{NaOH, HCl}} \text{p-Bromophenol (B)} \]
All the letters of the word "GTWENTY" are written in all possible ways with or without meaning, and these words are arranged as in a dictionary. The serial number of the word "GTWENTY" is: