Unbranched alkenes on ozonolysis give $:-$

Provide information about the structure and isomerism of alkenes.

When $HCl$ is treated with propene in the presence of sodium peroxide,the major product obtained is

$A$ hydrocarbon '$X$' with formula $C_6H_8$ uses two moles of $H_2$ on catalytic hydrogenation of its one mole. On ozonolysis,'$X$' yields two moles of methane dicarbaldehyde (malonaldehyde). The hydrocarbon '$X$' is :

On reductive ozonolysis,$1-$methylcyclohexene yields:

Compound $(A)$ is formed by the reaction of cyclooctatetraene with $(3 \text{ mole})$ of $CH_2I_2$ in the presence of $Zn/Cu$. Identify compound $(A)$.