How many of the following are primary amines

A) 3° butyl amine

B) 2° butyl amine

C) Isobutyl amine

D) Dimethyl amine

Amines are derivatives of ${\mathrm{NH}}_3$

I) $-{\mathrm{NH}}_2$ group is the functional group in 1° amines

II) $-\mathrm{NH}-$ group is the functional group in 2° amines

III) $-\underset{|}{\mathrm{N}}-$group is the functional group in 3° amines

A) ${\mathrm{CH}}_3-\stackrel{\underset{|}{{\mathrm{CH}}_3}}{\underset{\stackrel{|}{{\mathrm{CH}}_3}}{\mathrm{C}}}-{\mathrm{NH}}_2$ …1° amine

B) ${\mathrm{CH}}_3-\stackrel{\underset{|}{{\mathrm{NH}}_2}}{\mathrm{CH}}-{\mathrm{CH}}_2-{\mathrm{CH}}_3$ …1° amine

C) ${\mathrm{CH}}_3-\underset{\stackrel{|}{{\mathrm{CH}}_3}}{\mathrm{CH}}-{\mathrm{CH}}_2-{\mathrm{NH}}_2$ …1° amine

D) ${\mathrm{CH}}_3-\mathrm{NH}-{\mathrm{CH}}_3$ …2° amine