The correct order of basic strengths of the given amines is:

$A$ hydrocarbon $'A'$ $(C_4H_8)$ on reaction with $HCl$ gives a compound $'B'$ $(C_4H_9Cl)$,which on reaction with $1 \ mol$ of $NH_3$ gives compound $'C'$ $(C_4H_{11}N)$. On reacting with $NaNO_2$ and $HCl$ followed by treatment with water,compound $'C'$ yields an optically active alcohol,$'D'$. Ozonolysis of $'A'$ gives $2 \ mols$ of acetaldehyde. Identify compounds $'A'$ to $'D'$. Explain the reactions involved.

Among the compounds given below,the order of basicity is:
$(I)$ Piperidine
$(II)$ Pyridine
$(III)$ Morpholine
$(IV)$ Pyrrole

Match List-$I$ with List-$II$ :

List-$I$	List-$II$
$a$. Gabriel synthesis	$i$. Benzaldehyde
$b$. Kolbe synthesis	$ii$. Ethers
$c$. Williamson synthesis	$iii$. Primary amines
$d$. Etard reaction	$iv$. Salicylic acid

Choose the correct answer from the options given below :

Which set of products will be obtained in the following reactions?
$RCN \xrightarrow{\text{reduction}} (a)$
$RCN \xrightarrow[(ii) H_2O]{(i) CH_3MgBr} (b)$
$RNC \xrightarrow{\text{hydrolysis}} (c)$
$RNH_2 \xrightarrow{HNO_2} (d)$

Product $A$ is