The reaction of $1,1,2,2$-tetrabromoethane with zinc dust produces .............

Which of the following is Lindlar catalyst?

The major product of the following reaction is:

What is Lindlar's catalyst?

The correct order of acidic nature of the following alkynes is:
$I$. $HC \equiv CH$
$II$. $CH_3-C \equiv C-CH_3$
$III$. $CH_3-C \equiv CH$

The relation between $(B)$ and $(C)$ is:
$CH_3-C \equiv CH$ $\xrightarrow{NaNH_2}$ $\xrightarrow{CH_3-I} (A)$ $\xrightarrow{Li/liq. NH_3} (B)$
$CH_3-C \equiv CH$ $\xrightarrow{NaNH_2}$ $\xrightarrow{CH_3-I} (A)$ $\xrightarrow[Pd/CaCO_3]{H_2} (C)$