Which of the following reactants on reaction with conc. $NaOH$ followed by acidification gives the following lactone as the only product?

Which of the following reactions are incorrect?
$(a)$ $CH_2(COOH)_2 \xrightarrow{\Delta} CH_3COOH + CO_2$
$(b)$ Aniline $\xrightarrow{CH_3Cl/AlCl_3}$ $p$-chloroaniline
$(c)$ Phenol $\xrightarrow{CHCl_3 + aq. NaOH}$ Salicylic acid
$(d)$ $CH_3CHO + NaHSO_3 \rightleftharpoons CH_3CH(OH)SO_3Na$
$(e)$ Benzene $\xrightarrow{CO, HCl, Anhydrous AlCl_3/CuCl}$ Benzaldehyde

$A$ carbonyl compound $P$,which gives a positive iodoform test,undergoes reaction with $MeMgBr$ followed by dehydration to give an olefin $Q$. Ozonolysis of $Q$ leads to a dicarbonyl compound $R$,which undergoes intramolecular aldol reaction to give predominantly $S$.
$P$ $\xrightarrow[\substack{2. H^{+}, H_2 O \\ 3. H_2 SO_4, \Delta}]{1. MeMgBr} Q$ $\xrightarrow[2. Zn, H_2 O]{1. O_3} R$ $\xrightarrow[2. \Delta]{1. OH^{-}} S$
$1.$ The structure of the carbonyl compound $P$ is
$2.$ The structures of the products $Q$ and $R$,respectively,are
$3.$ The structure of the product $S$ is
Give the answer for questions $1, 2$ and $3.$

The given reaction is: $C_6H_5-CHO + C_6H_5-CHO \xrightarrow{Na_2[Fe(CO)_4]} C_6H_5-COOCH_2-C_6H_5$

Compare the rate of reaction toward Beckmann rearrangement for the given oxime derivatives where $\gamma$ is: $(i) CH_3COO^-$,$(ii) ClCH_2COO^-$,$(iii) PhSO_3^-$.

One mole of an organic compound requires $0.5$ mole of oxygen to produce an acid. The compound may be