Which of the following is picric acid?

An organic compound $A$ with empirical formula $C_6H_6O$ gives a sooty flame on burning. Its reaction with bromine solution in a low polarity solvent results in a high yield of $B$. $B$ is:

Given below are two statements:
Statement $I$: Phenol on treatment with $CHCl_3 / aq. KOH$ under refluxing condition, followed by acidification produces $p$-hydroxybenzaldehyde as the major product and $o$-hydroxybenzaldehyde as the minor product.
Statement $II$: The mixture of $p$-hydroxybenzaldehyde and $o$-hydroxybenzaldehyde can be easily separated through steam distillation.
In the light of the above statements, choose the correct answer from the options given below:

$C_6H_5OH \xrightarrow[Br_2]{OH^{\ominus}} ; $ Intermediate of the given reaction is/are

Identify '$Z$' in the following reaction: $Ar-OH + Cl-C(=O)-R \xrightarrow{\text{Pyridine}} Z + HCl$

Which of the following can not react with $NaHCO_3$?