Which of the following gives RNC when treated with CHCl3 and KOH?
This is Hoffmann's carbylamines test also called isocyanide test. It is given by aliphatic or aromatic primary amines. This test is not indicated by secondary or tertiary amines.
For example, aniline, chloroform and alc. KOH on heating gives foul smelling phenyl isocyanide.
C6H5−NH2Aniline+CHCl3+3KOHheat−−→C6H5−NCPhenylisocyanide+3KCl+3H2O
Option A is correct.