The correct choice is (a) Propanenitrile
To explain I would say: Ethylamine on heating with chloroform and ethanolic KOH forms an isocyanide, ethyl isocyanide (CH3CH2NC) along with KCl and H2O. This is known as carbylamines reaction. Propanenitrile (CH3CH2CN) is not formed as it is the cyanide form of ethyl isocyanide.