Reactant $(A)$ can be

Give the main product of the following reactions:
$(i)$ $1, 2-$dibromopropane + alcoholic $KOH$
$(ii)$ $1, 1, 2, 2-$tetrabromoethane + zinc powder in methanol

Give the reaction for the following conversions:
$1$. Ethyne from ethene via bromination
$2$. Bromoethane from ethyne

What is the major product in the given reaction?

What is the stereochemistry of the product formed in the following reaction?

What is the degree of unsaturation (double bond equivalent) in compound $(A)$?