A research scholar get a mixture of three product during an experiment with ammonia. In product I only one H of ammonia is replaced by ethyl group and in II two H atoms of ammonia are replaced by ethyl groups and in III all the H- atoms are replaced by ethyl groups. Which test he should use to distinguish or separate the products `:`
A. Carbyl amine test
B. Iodoform test
C. Fehling solution test
D. Hinsbert test
