Which compound is a secondary amine

[Step 1]:Option (1) Methyl amine is CH3−NH2  is a primary amine[Step 2]:Option (2) Aniline is C6H5−NH2  is a primary amine[Step 3]:Option (3) di methyl amine is CH3−NH−CH3  is a secondary amine[Step 4]:Option (4) ethane amine is  C2H5NH2 is a primary amine