Which reactants are used to prepare $cis$ and $trans$ alkenes from alkynes?

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

Identify the alkyne in the following sequence of reactions:

But$-1-$yne on reaction with dil. $H_2SO_4$ in the presence of $Hg^{2+}$ ions at $333 \ K$ gives:

In the reaction $HC \equiv CH + 2AgNO_3 \xrightarrow{NH_4OH} X + 2NH_4NO_3 + 2H_2O$,'$X$' is:

When $23 \ g$ of $Na$ reacts with $1 \ mole$ of propyne,how many moles of $H_2$ gas will be released?