Which reacts with ammoniacal $AgNO_3$?

What is the final product,$C$ of the following reaction sequence?
$CH_3CH_2-C \equiv CH$ $\xrightarrow[2. CH_3CH_2Br]{1. NaNH_2} A$ $\xrightarrow{Na, NH_3(liq.)} B$ $\xrightarrow{Br_2, CH_2Cl_2} C$

What are $X$ and $Y$ respectively in the following reaction?
$Z$-product $\stackrel{Y}{\longleftarrow} 2$-butyne $\stackrel{X}{\longrightarrow} E$-product

Consider the following sequence,where $A$ can be:
$A$ $(C_{3}H_{6}Cl_{2})$ $\xrightarrow[2. \, H^{+} \, (mild)]{1. \, \text{alcoholic } KOH / \Delta, \text{ followed by } NaNH_{2} / \Delta}$ $B$ $\xrightarrow[H_{2}O_{2} / OH^{-}]{B_{2}H_{6}}$ $C$
$A$ $\xrightarrow{aq. \, KOH \, (excess)}$ $C$
Identify $A$.

The product $Z$ of the following reaction is
$CH_3-C \equiv CH \xrightarrow{2 HBr} Z$

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