What product is obtained when acetylene is passed through dilute sulfuric acid containing $Hg^{2+}$ ions?

$CH \equiv CH$ $\xrightarrow[H_2SO_4]{H_2O/Hg^{2+}} X$ $\xrightarrow{LiAlH_4} Y$ $\xrightarrow{P_4/Br_2} Z$. Here $Z$ is

Acetylene gives

The $-C \equiv C-$ bond is found in

What is the major product of the following reaction? $CH_3-C \equiv C-CH_2-CH_3 \xrightarrow{1 \ mol \ of \ Cl_2} \text{?}$

In order to complete the reaction $1-Pentyne$ $\xrightarrow{a} 4-Octyne$ $\xrightarrow{b} cis-4-Octene$,$a$ and $b$ will be:
$A) NaNH_2; CH_3CH_2CH_2Br : H_2, (1 \ mole) \text{ Lindlar catalyst}$
$B) NaNH_2; CH_3CH_2CH_2Br : H_2, (2 \ moles) \text{ Pd or Ni}$
$C) NaNH_2; CH_3CH_2CH_2Br : H_2, (1 \ mole) \text{ Pd or Ni}$
$D) NaNH_2; CH_3CH_2CH_2Br : BH_3, H_2O_2, OH^-$