The formation of which of the following polymers involves hydrolysis reaction?

The nylon -6 is obtained by the condensation reaction. It is prepared by the polymerization of aminocaproic acid at high temperatures. It is also known as the Caprolactam. Caprolactam is first hydrolysed with the water to form the amino acid on heating undergoes the polymerization reaction to produce the nylon-6 polymer. Thus, (a) is the correct option.