A. Ammonia
B. 1°Alkyl ammine
C. 2° Alkyl ammine
D. 3° Alkyl ammine
In general, primary amines are less basic than secondary and tertiary amines due to the presence of an additional alkyl or aryl group in the latter. This electron-donating group increases the electron density on the nitrogen atom, making it more basic. As a result, tertiary amines are the most basic of the three, followed by secondary amines, and then primary amines. Ammonia, being a simple primary amine, is less basic than the alkyl-substituted amines, making it the least basic of the four compounds listed in the question.
Submitted by :- Jamil Ahmed