The correct option is A C2H5NH2+CHCl3+3KOHwarm−−−→CH3CH2NC+3KCl+3H2O
The following reaction is called carbylamine reaction (or isocyanide test).
C2H5NH2+CHCl3+3KOHwarm−−−→CH3CH2NC+3KCl+3H2O
Aliphatic and aromatic primary amines when warmed with chloroform and an alcoholic solution of KOH, form isocyanide or carbylamine which have very unpleasant or foul smell.