Which reagent is used in the conversion of phenol to picric acid?

Which of the following compounds $(i)$ and $(ii)$ will not react with a mixture of $NaBr$ and $H_{2}SO_{4}$? Explain why?
$(i)$ $CH_{3}CH_{2}CH_{2}OH$
$(ii)$ Phenol (as shown in the image)

$A + CCl_4 + KOH \to$ Salicylic acid
'$A$' in the above reaction is

The correct order of boiling point for the given compounds is:

$C_6H_6 + X \xrightarrow{anhydrous AlCl_3} \text{Isopropylbenzene} \xrightarrow{(i) O_2, (ii) H^+} Y + Z$. In this reaction,$X, Y$ and $Z$ are . . . . . . respectively.

Explain how the $-OH$ group attached to a carbon of a benzene ring activates it towards electrophilic substitution.