Identify the correct statement regarding the following sequence of reactions:
$3\text{-methylbut-1-ene}$ $\xrightarrow[(ii) NaBH_4]{(i) Hg(OCOCH_3)_2/H_2O} A$ $\xrightarrow{\Delta, H_2SO_4} B (\text{major alkene})$ $\xrightarrow{O_3/Zn} C + D$

Compounds $P$ and $R$ upon ozonolysis produce $Q$ and $S$,respectively. The molecular formula of $Q$ and $S$ is $C_8H_8O$. $Q$ undergoes Cannizzaro reaction but not haloform reaction,whereas $S$ undergoes haloform reaction but not Cannizzaro reaction.
$(i)$ $P \xrightarrow[\text{ii) } Zn / H_2O]{\text{i) } O_3 / CH_2Cl_2} \underset{(C_8H_8O)}{Q}$
$(ii)$ $R \xrightarrow[\text{ii) } Zn / H_2O]{\text{i) } O_3 / CH_2Cl_2} \underset{(C_8H_8O)}{S}$
The option$(s)$ with a suitable combination of $P$ and $R$,respectively,is(are):

Oxidation of ketones involves carbon-carbon bond cleavage. Name the products formed on the oxidation of $2,5-$dimethylhexan$-3-$one.

The carbonyl compound that does not undergo aldol condensation is

Which reaction is correctly matched with its name?

An organic compound $x$ where the molar ratio of $C$, $O$, and $H$ are equal, on treatment with $50\% \ KOH$ under reflux followed by acidification produced $y$. The most likely structure of $y$ is: [Molar mass of $x$ is $58 \ g \ mol^{-1}$]