Which of the following reactions give $RCONH_2$?

Compound $A$ was prepared by oxidation of compound $B$ with alkaline $KMnO_4$. Compound $A$ on reduction with lithium aluminium hydride $(LiAlH_4)$ gets converted back to compound $B$. When compound $A$ is heated with compound $B$ in the presence of $H_2SO_4$,it produces a fruity smell of compound $C$. To which family do the compounds $A$,$B$,and $C$ belong?

The product of the following reaction is :

Assertion : $RCOCl$,$(RCO)_2O$ and $RCOOR'$ all react with Grignard reagents to form $3^o$ alcohols.
Reason : $RCOCl$ reacts with $R_2Cd$ to form ketones but $(RCO)_2O$ and $RCOOR'$ do not react at all.

Hydrolysis of an ester gives a carboxylic acid which on Kolbe's electrolysis yields ethane. The ester is

Which of the following compounds on hydrolysis gives reactant $(A)$?