What are $B$ and $C$ respectively in the following set of reactions?
$C \xleftarrow[\Delta]{Zn} 1,2-\text{dibromopropane}$ $\xrightarrow[\text {(ii) } NaNH_2]{\text {(i) alc. } KOH} A$ $\xrightarrow[\text { Catalyst }]{\text { Lindlar }} B$

"$P$" 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:

Which of the following reactions produce the same product?

If the following compound is treated with $Pd/C$ in excess of hydrogen gas,how many stereoisomers of the product will be obtained?

Identify the correct order of heat of hydrogenation.

Cyclohexane,a hydrocarbon,floats on water because: