Which method can be used to prepare $Propane$ from $Propene$?

The product $(P)$ is:

The $IUPAC$ names of some alkenes are given below. Determine the correct stability order: $A$. $2$-Methylbut-$2$-ene,$B$. $cis$-But-$2$-ene,$C$. $2,3$-Dimethylbut-$2$-ene,$D$. Prop-$1$-ene.

The number of acyclic structural isomers (including geometrical isomers) for pentene $(C_5H_{10})$ are $......$

Ethylene reacts with bromine to form

$A$ hydrocarbon of formula $C_6H_{10}$ absorbs only one molecule of $H_2$ upon catalytic hydrogenation. Upon ozonolysis,the hydrocarbon yields $OHC-CH_2-CH_2-CH_2-CH_2-CHO$. The hydrocarbon is: