In order to prepare a `1^(@)`- amine incorporating an additional `CH_(2)` group from an alkyl halide, What reagent is often used as the nitrogen soure?
A. Sodium amide `NaNH_(2)`
B. Sodium azide ,`NaN_(3)`
C. potassium cyanide,KCN
D. Potassium phthalimide,`C_(6)H_(4)(CO)_(2)NK`