When an alcoholic solution of ethylene dibromide $(Br-CH_2-CH_2-Br)$ is heated with granulated zinc,the compound formed is:

For which of the following reactions is Markovnikov's rule most applicable?

The reaction of an alkene $X$ with bromine produces a compound $Y$,which has $22.22 \% \ C$,$3.71 \% \ H$ and $74.07 \% \ Br$. The ozonolysis of alkene $X$ gives only one product. The alkene $X$ is,
[Given,atomic mass of $C = 12$; $H = 1$; $Br = 80$ ]

On reductive ozonolysis,$1-$methylcyclohexene yields:

Two alkenes,$X$ ($91\%$ yield) and $Y$ ($9\%$ yield),are formed when the following compound is heated:
The structures of $X$ and $Y$,respectively,are:

$CH_3-CH=CH_2 \xrightarrow{HBr} \text{Major product } (A). \text{ } A \text{ is:}$