Which of the following reaction is an example of ammonolysis?

Ammonolysis is the reaction in which ammonia ($$NH_3$$) acts as the nucleophile and replaces a leaving group (such as a halide) in a substrate, forming a new C-N bond. The term specifically refers to cleavage by ammonia, analogous to how hydrolysis is cleavage by water.

Looking at the options: option (1) is an acylation reaction of an amine with an acid chloride (Schotten-Baumann reaction), option (2) is a reduction of a nitrile to a primary amine, and option (3) is a simple acid-base reaction forming an ammonium salt.

Option (4), $$C_6H_5CH_2Cl + NH_3 \to C_6H_5CH_2NH_2$$, is the reaction of benzyl chloride with ammonia where $$NH_3$$ displaces the chloride via nucleophilic substitution, which is the textbook definition of ammonolysis. The correct answer is option (4).