In organic chemistry, the suffix "-amine" indicates the presence of an amino group (-NH2). For compounds like allyl amine, numbering is done from the carbon closest to the functional group.
Allyl amine is an organic compound with the formula \( CH_2=CH-CH_2NH_2 \). It consists of a propene (propylene) backbone with an amino group (-NH2) attached to the second carbon.
The IUPAC name for this compound is "2-aminopropene," as the amino group is attached to the second carbon of the propene chain.
Thus, the correct answer is \( B \).