Which of the following is $\underline{NOT}$ a dihydric phenol?

The major products of the following reaction are:

In the given reaction sequence,identify the processes $X$ and $Y$ respectively to obtain salicylaldehyde from chlorobenzene:
$Chlorobenzene$ $\xrightarrow{X} Phenol$ $\xrightarrow{Y} Salicylaldehyde$

In the presence of $NaOH$,phenol reacts with $CHCl_3$ to form $o$-hydroxybenzaldehyde. This reaction is called:

Heating benzoic acid with $X$ or phenol with $Y$ gives benzene. $X$ and $Y$ are respectively:

Among $(i)-(iii)$,the boiling point follows the order: