Among the following,which is least acidic?

Which compound does not react with $NaHCO_3$?

Product $(A)$ and $(B)$ respectively are $:-$

What are $X$ and $Y$ respectively in the following set of reactions?

The correct statement$(s)$ about the following reaction sequence is(are):
Cumene $(C_9H_{12})$ $\xrightarrow[ii) H_3O^+]{i) O_2}$ $P$ $\xrightarrow{CHCl_3/NaOH}$ $Q$ (major) + $R$ (minor)
$Q$ $\xrightarrow[PhCH_2Br]{NaOH}$ $S$
$(A)$ $R$ is steam volatile
$(B)$ $Q$ gives dark violet coloration with $1 \%$ aqueous $FeCl_3$ solution
$(C)$ $S$ gives yellow precipitate with $2, 4-dinitrophenylhydrazine$
$(D)$ $S$ gives dark violet coloration with $1 \%$ aqueous $FeCl_3$ solution

Phenol $\xrightarrow{Br_2 / H_2O}$ Product formed is