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

$But-2-yne$ and hydrogen (one mole each) are separately treated with $(i)$ $Pd / C$ and $(ii)$ $Na / \text{liq. } NH_3$ to give the products $X$ and $Y$ respectively. Identify the incorrect statements.
$A$. $X$ and $Y$ are stereoisomers.
$B$. Dipole moment of $X$ is zero.
$C$. Boiling point of $X$ is higher than $Y$.
$D$. $X$ and $Y$ react with $O_3 / Zn + H_2O$ to give different products.
Choose the correct answer from the options given below:

Which of these will not react with acetylene?

Identify the correct order of acidic strength for the following hydrocarbons:

Benzene is the polymer of

When acetylene is reacted with $HBr$,we get