Polyamides are polymers where they are made of repeating units that are connected together by amide bonds.
Most commonly known example for a polyamide is proteins. Proteins are made of amino acids. Amino acid consists of both a carboxylic acid and amine group. When the carboxylic group of one bonds to the amine group of the adjacent amino acid, it removes a water molecule during the bond formation. The bond formed is a called an amide bond.
The units forming the polyamide are linked together by amide bonds.
Correct answer is A. Reaction is formed between Carboxylic acid and amine