The major product $A$ is:

Match the following reactions in List-$I$ with their products in List-$II$:

List-$I$	List-$II$
$A$. The reaction of $1,6$-dibromohexane with $Zn$.	$i$. $H_3C-C \equiv CH$
$B$. Reaction of ethanol with concentrated $H_2SO_4$ at $443 \ K$.	$ii$. $H_2C=CH_2$
$C$. Major product in the reaction of propene with $HBr$ in the presence of benzoyl peroxide.	$iii$. $CH_3-CH_2-CH_2-Br$
$D$. The reaction of $1,1$-dibromopropane with $NaNH_2$ at $433 \ K$.	$iv$. Cyclohexane

An organic compound $C_8H_{12}$ on ozonolysis gives $2 \ moles$ of $3-$oxobutanal. Then the structure of the compound can not be

$Ph-C \equiv C-CH_3 \xrightarrow{Hg^{2+}/H^{+}} A$. $A$ is

In the given sequence of reactions,identify $P, Q, R$ and $S$ respectively.
$CH_2=CH_2 + Br_2$ $\xrightarrow{P} CH_2(Br)-CH_2(Br)$ $\xrightarrow{Q} CH_2=CH-Br$ $\xrightarrow{R} CH \equiv CH$ $\xrightarrow{S} C_6H_6$

Which of the following does **$NOT$** liberate $H_2$ gas on reaction with $Na$ metal?