What is the product $(A)$ in the following reaction?

In $S_{N}2$ reactions,the correct order of reactivity for the following compounds:

Major products $A$ and $B$ formed in the following reaction sequence are:

$A$ bottle containing $C_6H_5I$ and $C_6H_5CH_2I$ has lost its label. To identify them,samples $A$ and $B$ are taken in separate test tubes and boiled with $NaOH$ solution. Finally,the solution in each test tube is acidified with dilute $HNO_3$ and then a few drops of $AgNO_3$ solution are added. Substance $B$ gives a yellow precipitate. Which statement is correct for this process?

Benzyl bromide on reaction with magnesium in the presence of dry ether gives $'X'$. $'X'$ on reaction with ethanol gives $'Y'$. Then the compound $Y$ is

Identify '$X$' and '$Y$' in the following sequence of transformations: $CH_3-CH_2-CH_2Br$ $\xrightarrow{X} \text{Product}$ $\xrightarrow{Y} CH_3-CH(Br)-CH_3$.