Which pair of reactant compounds may be used to make the given acetal?

Reaction of iso-propylbenzene with $O_2$ followed by treatment with $H_3O^{+}$ forms phenol and a by-product $P$. Reaction of $P$ with $3$ equivalents of $Cl_2$ gives compound $Q$. Treatment of $Q$ with $Ca(OH)_2$ produces compound $R$ and calcium salt $S$. The correct statement(s) regarding $P, Q, R$ and $S$ is(are):
$(A)$ Reaction of $P$ with $R$ in the presence of $KOH$ gives chloritone.
$(B)$ Reaction of $R$ with $O_2$ in the presence of light gives phosgene gas.
$(C)$ $Q$ reacts with aqueous $NaOH$ to produce $Cl_3CCH_2OH$ and $Cl_3CCOONa$.
$(D)$ $S$ on heating gives $P$.

$A$ 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 $3.$

Acetone and acetaldehyde are differentiated by

The major products in the reaction $Br_3CCHO \stackrel{NaOH}{\longrightarrow}$ are $....$

Reactant $(A)$ is: