Benzotrichloride reacts with milk of lime to form

The oxidation of ethylbenzene with $KMnO_4$ yields which of the following compounds?

$Ph-C(=O)-CH_3$ $\xrightarrow[HCl]{NaNO_2} (A)$ $\xrightarrow[heat]{Ac_2O} (B)$ $\xrightarrow{H_3O^{+}} (C)$
Product $(C)$ of the above reaction is

What is obtained by the hydrolysis of methyl cyanide in the presence of an acid?

Acid $D$ formed in the reaction sequence is:

Toluene on reaction with reagent $A$ gives $X$. This $(X)$ forms $2,4-$dinitrophenylhydrazone and reduces ammonical silver nitrate solution. Reaction of toluene with another reagent $B$ forms $Y$,which dissolves in $NaHCO_3$ with evolution of $CO_2$. What are $A$ and $B$ respectively?