Which of the following compounds is the most acidic?

Match the reaction in Column-$I$ with the product in Column-$II$.

Column-$I$ (Reaction)	Column-$II$ (Product)
$(A)$ Dinitration of $4$-methylphenol	$(i)$ $2$-nitro-$4$-methylphenol + $2$-nitro-$5$-methylphenol
$(B)$ Mononitration of phenyl ethanoate	$(ii)$ $2,4$-dinitro-$5$-methylphenol
$(C)$ Dinitration of $3$-methylphenol	$(iii)$ $4$-nitrophenyl ethanoate
$(D)$ Mononitration of $3$-methylphenol	$(iv)$ $2,6$-dinitro-$4$-methylphenol

Which one of the following compounds is most acidic?

The following reaction sequence is given:
Phenol $\xrightarrow{NaOH} X$ $\xrightarrow[(ii) H^+]{(i) CO_2} Y$ $\xrightarrow{(CH_3CO)_2O/H^+} Z + CH_3COOH$
The correct statements about $Z$ from the following are:
$I$. It is $o$-hydroxybenzoic acid.
$II$. It is a non-narcotic analgesic.
$III$. It acts as antipyretic.
$IV$. It acts as antihistamine.

Among the following four compounds:
$(i)$ Phenol
$(ii)$ Methyl phenol
$(iii)$ Meta-nitrophenol
$(iv)$ Para-nitrophenol
The acidity order is:

Write the nitration and bromination reactions of phenol.