Which one of the following on reduction with lithium aluminium hydride yields a secondary amine?

1. Nitroethane (${\text{CH}}_3{\text{CH}}_2{\text{NO}}_2$) reduces to ${\text{CH}}_3{\text{CH}}_2{\text{NH}}_2$ (primary amine).2. Methylisocyanide (${\text{CH}}_3\text{NC}$) reduces to ${\text{CH}}_3{\text{NHCH}}_3$ (dimethylamine, a secondary amine).3. Acetamide (${\text{CH}}_3{\text{CONH}}_2$) reduces to ${\text{CH}}_3{\text{CH}}_2{\text{NH}}_2$ (primary amine).4. Methyl cyanide (${\text{CH}}_3\text{CN}$) reduces to ${\text{CH}}_3{\text{CH}}_2{\text{NH}}_2$ (primary amine).