Which of the following reactions produce the same product?

The main product of the following reaction is:

The number of sigma $(σ)$ and pi $(π)$ bonds in pent$-2-$en$-4-$yne is

The product $(Z)$ is:

Which of the following is $NOT$ a hydrocarbon?

"$P$" 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: