Acetylene can be prepared from

The product$(s)$ obtained via oxymercuration $(HgSO_4 + H_2SO_4)$ of $1$-butyne would be:

In the acetylene molecule,the two carbon atoms are linked by:

The trend in acidic behaviour of the following hydrocarbons is:
$a: HC \equiv CH$
$b: CH_2 = CH_2$
$c: CH_3 - CH_3$
$d: CH_3 - C \equiv CH$

The major organic compound formed by the reaction of $1, 1, 1-$trichloroethane with silver powder is:

If acetylene is passed through an electric arc in the atmosphere of nitrogen,the compound formed is