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

Which of the following is formed when propene is heated with bromine at high temperature?

Reaction of one molecule of $HBr$ with one molecule of $1,3-$butadiene at $40\,^{\circ}C$ gives predominantly

The boiling point (in $K$) of $cis-but-2-ene$ and dipole moment (in $D$) of $trans-but-2-ene$ are respectively:

$CH_3-CH(CO_2K)-CH(CO_2K)-CH_3 \xrightarrow{\text{electrolysis}} (A) \text{ (Major)}$
The major product $(A)$ of the above reaction is:

The major product of the reaction of $1,3$-cyclohexadiene with $1 \text{ mole}$ of $HBr$ is: