Which of the following compounds will undergo $S_{N^1}$ reaction most easily?

Match the following reactants with their corresponding products:
Reactants:
$(A)$ $C_2H_5Cl$,moist $Ag_2O$
$(B)$ $C_2H_5Cl$,ethanolic $AgCN$
$(C)$ $C_2H_5Cl$,ethanolic $AgNO_2$
$(D)$ $C_2H_5Cl$,ethanolic $KOH$
Products:
$(i)$ $CH_3CH_2ONO$
$(ii)$ $C_2H_4$
$(iii)$ $CH_3CH_2OH$
$(iv)$ $CH_3CH_2NC$
Select the correct match:

An isomer of $C_5H_{12}$ on reaction with $Br_2 / \text{light}$ gave only one isomer $C_5H_{11}Br(X)$. Reaction of $X$ with $AgNO_2$ gave $Y$ as the major product. What is $Y$?

Which is the correct decreasing order of boiling points for the following compounds?

The major product $(A)$ formed in the reaction given below is:

$2-$Methylpropyl bromide reacts with $C_2H_5O^-$ to give $A$,whereas on reaction with $C_2H_5OH$ it gives $B$. The mechanism followed in these reactions and the products $A$ and $B$ respectively are: