$C_6H_5 - C \equiv C - CH_3 \xrightarrow{HgSO_4, H_2SO_4} A$

Identify the major product $A$ in the following reaction sequence:
$CH_3-CH=CH-CH_3$ $\xrightarrow[CCl_4]{Br_2}$ $\xrightarrow[(ii) NaNH_2]{(i) alc. KOH} (A)$

When calcium carbide is reacted with heavy water,which of the following product$(s)$ will be formed?
$I$. $CD_4$
$II$. $C_2D_2$
$III$. $Ca(OD)_2$
$IV$. $Ca_2 \cdot D_2O$

In the following reaction:
$C_2H_2$ $\xrightarrow[HgSO_4 / H_2SO_4]{H_2O} (x)$ $\xrightarrow{\text{Tautomerisation}} CH_3-CHO$
$(x)$ is $:-$

The reaction $Ph-C \equiv CH \xrightarrow[{(2)\,H_2O_2/OH^{-}}]{{(1)\,BH_3.THF}}$ Product; the product is

Identify the product $D$ in the following series of reaction: $CH_3COOH$ $\xrightarrow{LiAlH_4} A$ $\xrightarrow{H^{+}, 443 \ K} B$ $\xrightarrow{Br_2} C$ $\xrightarrow{alc. KOH} D$