Which of the following is the strongest Bronsted acid?

The structure of the compound that gives a tribromo derivative on treatment with bromine water is

Choose the incorrect option based on the reaction:
$(P)$ + $CH_3-CO-Cl \rightarrow (Q)$
Where $(P)$ is salicylic acid and the structure of $(Q)$ is given as:
$(Q)$ is a benzene ring with an $-OH$ group and a $-COO-CO-CH_3$ group at ortho position.

$4.7 \text{ g}$ of phenol is heated with $Zn$ to give product $X$. If this reaction goes to $60\%$ completion, then the number of moles of compound $X$ formed will be . . . . . . $\times 10^{-2}$. (Nearest Integer) (Given molar mass in $\text{g mol}^{-1}$: $H:1, C:12, O:16$)

The nitration of phenol with dilute $HNO_3$ at low temperature yields a mixture of two isomers $(A)$ and $(B)$. Product $(A)$ is more volatile than product $(B)$. Identify $(A)$.

$Phenol$ $\xrightarrow[Distillation]{Zn} A$ $\xrightarrow[Conc. H_2SO_4]{Conc. HNO_3} B$ $\xrightarrow[NaOH]{Zn} C$
In the above reaction,$A$,$B$,and $C$ are the following compounds: