An amine is classified based on the number of carbon atoms directly bonded to the nitrogen atom. An amine is classified as primary, secondary, or tertiary based on the number of alkyl or aryl groups (carbon-containing groups) attached directly to the nitrogen atom.

B. tertiary amine: A tertiary amine has the nitrogen atom bonded to three carbon-containing groups and no hydrogen atoms.

C. quaternary amine: A quaternary amine (or quaternary ammonium salt) has the nitrogen atom bonded to four carbon-containing groups and carries a positive charge (it is an ion, not a neutral amine).

D. secondary amine: A secondary amine has the nitrogen atom bonded to two carbon-containing groups and one hydrogen atom.

In the compound CH\(_3\)CH(NH\(_2\))CH\(_2\)CH\(_2\)CH\(_3\),(also known as 2-pentanamine), the nitrogen atom is bonded to two hydrogen atoms and one alkyl group (the pentan-2-yl group). However, since the nitrogen atom is bonded to only one carbon-containing group, it is a primary amine.

The correct answer is primary amine - option A