The structure shown is R-C(=O)-NH-H, which contains a carbonyl group (C=O) directly bonded to a nitrogen atom bearing hydrogen atoms. This is the defining arrangement of the amide functional group (-CONH2).
An alkanamide (also called an amide) has the general formula R-CONH2, where R is an alkyl group. The key feature distinguishing it from the other options is the simultaneous presence of both the C=O and the N-H bonds on the same carbon.
An alkylamine (R-NH2) has nitrogen bonded to an alkyl group but no carbonyl. An alkanone (R-CO-R') has a carbonyl flanked by two carbon groups with no nitrogen. An amino acid would require both an amine group (-NH2) and a carboxyl group (-COOH) on the same molecule, which is not the case here.
