The major product of the given reaction is:

What is the product $(Q)$ of the following reaction?

$A$ sample of petrol is a mixture of $30\%$ $n$-heptane and $70\%$ iso-octane. The sample has an octane number of:

The decreasing order of heat evolved upon catalytic hydrogenation of the given reactants with $H_2\ (Pd/C)$ is:

Product $(B)$ of the reaction is

"$P$" is a hydrocarbon with the molecular formula $C_8H_{14}$. On ozonolysis,"$P$" forms "$Q$". "$Q$" on treatment with alkali under reflux conditions produces "$R$",which on treatment with $I_2/NaOH$ gives a yellow precipitate. Acidification of the solution gives "$S$". The structure of "$S$" is given below:
(Structure $S$: $1-$methyl$-2-$oxocyclopentanecarboxylic acid derivative or similar cyclic structure as per common reaction pathways).
The correct structure of "$P$" is: