Which of the following is a diagnostic test for aliphatic and aromatic primary amines? 

Carbylamine test

The correct answer is option 2. Carbylamine test.

The Carbylamine test, also known as the Isocyanide test or the Isonitrile test, is a diagnostic test for distinguishing between aliphatic and aromatic primary amines.

Reaction with Chloroform and Alcoholic Potassium Hydroxide: In this test, the primary amine is treated with chloroform (\( CHCl_3 \)) and alcoholic potassium hydroxide (\( KOH \)).

Formation of Isocyanide (Carbylamine): The primary amine reacts with chloroform and alcoholic potassium hydroxide to form an isocyanide (carbylamine) derivative. This isocyanide derivative has a distinct, foul odor, reminiscent of mustard oil.

Observation: The formation of the foul-smelling isocyanide confirms the presence of a primary amine. The intensity of the odor can indicate the presence of aromatic or aliphatic amines.

Other Tests:

Lassigne's Test: This test is used to distinguish between secondary and tertiary amines. It involves the formation of insoluble precipitates.

Lucas Test: This test is used to distinguish between primary, secondary, and tertiary alcohols based on their reactivity with concentrated hydrochloric acid and zinc chloride.

Victor-Meyer Test: This test is used to distinguish between primary, secondary, and tertiary amines based on their boiling points and solubility in water.

Among the given options, the Carbylamine test is specifically used as a diagnostic test for aliphatic and aromatic primary amines.

Therefore, the correct answer is Carbylamine test.