What is the structure of the major product when phenol is treated with bromine water?

The product $(A)$ in the following reaction is:

The ascending order of acidity of the $-OH$ group in the following compounds is:
$A$. $Bu-OH$
$B$. $p$-nitrophenol
$C$. $p$-methoxyphenol
$D$. Phenol
$E$. $2,4$-dinitrophenol
Choose the correct answer from the options given below:

The strongest acid among the following aromatic compounds is

The most suitable method for the separation of a $1:1$ mixture of $o-$ and $p-$ nitrophenols is:

Which of the following compounds will produce effervescence when mixed with an aqueous sodium bicarbonate $(NaHCO_3)$ solution?