When $but-3-en-2-ol$ reacts with aqueous $HBr$,the product formed is:

Match the following lists:

List-$I$	List-$II$
$(A)$ Benzene	$1$. Phosgene
$(B)$ Ethylene	$2$. Silver mirror
$(C)$ Acetaldehyde	$3$. Mustard gas
$(D)$ Chloroform	$4$. $(4n + 2) \pi$ electrons
	$5$. Carbylamine

$A$ (organic compound) $+ O_2 \to X + Y + Z$. Compound $(A)$ in pure form does not give a precipitate with $AgNO_3$ solution. $A$ mixture containing $70\%$ of $(A)$ and $30\%$ of ether is used as an anaesthetic. Compound $(X)$ and $(Y)$ are oxides while $(Z)$ is a pungent smelling gas. $(X)$ is a neutral oxide which turns cobalt chloride paper pink. Compound $(Y)$ turns lime water milky and produces an acidic solution with water. Compounds $(A), (X), (Y)$ and $(Z)$ respectively will be:

The product $A$ is
$4-methylcyclohexyl bromide + OH^- \xrightarrow{S_N2} A$

The structure of the major product formed in the following reaction is