Electrolysis of cold concentrated aqueous solution of potassium succinate yields:

Name the reaction,heating of $1,2-$dibromoethane with zinc powder?

The major product of the above reaction is

In the reaction
$CH_3-CH=CH_2$ $\xrightarrow{Cl_2/500\,^{\circ}C} A$ $\xrightarrow{Na/\text{dry ether}} B$
$B$ is

$A$ compound $A$ on reaction with $X$ and $Y$ produces the same major product but different by-products $a$ and $b$. Oxidation of $a$ gives a substance produced by ants.
$X$ and $Y$ respectively are :

Which of the following aliphatic compounds will discharge the red colour of bromine?