Metallic sodium does not react normally with:

$2-$butyne is reduced to $trans-but-2-ene$ using:

Ethyne on reaction with water in the presence of $HgSO_4$ and $H_2SO_4$ gives

$C_2H_2$ $\xrightarrow{\text{dil. } H_2SO_4, HgSO_4} A$ $\xrightarrow{[O]} B$ $\xrightarrow{NaOH} C$ $\xrightarrow{NaOH/CaO} D$
$[D]$ is -

Final product of the reaction
$CH_3-CH=CH_2$ $\xrightarrow[CCl_4]{Br_2} A$ $\xrightarrow[(3 \ mol)]{NaNH_2} B$ $\xrightarrow{CH_3-Br} C$ $\xrightarrow[Pd-BaSO_4]{H_2} D$

The hydration of propyne results in the formation of: