Final answer:
The compound d) (CH₃)₃CNH₂ is a primary amine, named trimethylamine, with the nitrogen atom bonded to three methyl groups and one hydrogen atom.
Step-by-step explanation:
Primary amines are characterized by their nitrogen atom being bonded to one alkyl group and two hydrogen atoms. Among the options given, d) (CH₃)₃CNH₂ is a primary amine. It is called trimethylamine because it has three methyl groups attached to the nitrogen atom, and the formula suggests that there is one additional hydrogen atom attached, making it primary. In contrast, the other compounds listed are either secondary amines, having the nitrogen attached to two carbon groups and one hydrogen atom, or tertiary amines, where the nitrogen is attached to three carbon groups. For example, c) CH₃CH₂N(CH₃)₂ is a secondary amine as the nitrogen atom is bonded to an ethyl and two methyl groups, leaving only one hydrogen attached directly to the nitrogen.