What happens when (Give chemical equations): (a) Propanone is treated with and then hydrolysed. (b)…

What happens when (Give chemical equations): (a) Propanone is treated with $\text{CH}_3\text{MgBr}$ and then hydrolysed. (b) Formaldehyde undergoes Cannizzaro’s reaction. (c) Acetic acid reacts with $\text{SOCl}_2$ and the main product obtained is reduced with $\text{H}_2$ in the presence of $\text{Pd}/\text{BaSO}_4$.

An aromatic compound [A] gives a buff-coloured precipitate on treatment with neutral $\text{FeCl}_3$ solution. Compound [A] reacts with thionyl chloride to give compound [B], which on reacting with ammonia followed by heating gives compound [C]. Compound [C] on treatment with bromine in $\text{KOH}$ forms [D] with molecular formula $\text{C}_6\text{H}_7\text{N}$ and has a characteristic odour. Identify the compounds [A], [B], [C] and [D].