Benzene on reaction with $A$ forms acetophenone,which on reaction with $B$ forms ethylbenzene. $A$ and $B$ are:

An organic compound $P$ having molecular formula $C_6H_6O_3$ gives a ferric chloride test and does not have an intramolecular hydrogen bond. The compound $P$ reacts with $3$ equivalents of $NH_2OH$ to produce oxime $Q$. Treatment of $P$ with excess methyl iodide in the presence of $KOH$ produces compound $R$ as the major product. Reaction of $R$ with excess iso-butylmagnesium bromide followed by treatment with $H_3O^{+}$ gives compound $S$ as the major product. The total number of methyl $(-CH_3)$ groups in compound $S$ is . . . .

Which of the following compounds will undergo self-aldol condensation in the presence of cold dilute alkali?

Identify the compound $A$ in the following reaction: $A + CH_3MgBr$ $\xrightarrow{\text{dry ether}} \text{intermediate}$ $\xrightarrow{H_3O^+} CH_3CH_2OH + Mg(Br)(OH)$

Match List-$I$ with List-$II$.

List-$I$ (Reactions)	List-$II$ (Reagents)
$(A)$ $CH_3(CH_2)_5COOC_2H_5 \rightarrow CH_3(CH_2)_5CHO$	$(I)$ $CH_3MgBr, H_2O$
$(B)$ $C_6H_5COC_6H_5 \rightarrow C_6H_5CH_2C_6H_5$	$(II)$ $Zn(Hg)$ and conc. $HCl$
$(C)$ $C_6H_5CHO \rightarrow C_6H_5CH(OH)CH_3$	$(III)$ $NaBH_4, H^+$
$(D)$ $CH_3COCH_2COOC_2H_5 \rightarrow CH_3CH(OH)CH_2COOC_2H_5$	$(IV)$ $DIBAL-H, H_2O$

Choose the correct answer from the options given below:

Among the given pairs,in which pair does the second compound have less enol content than the first compound?