Monomer A is reacted with a monomer B in boiling methanol to form a salt. The salt dissolved in water with a little amount of acetic acid is then processed in autoclave at different temperatures and pressure. Monomer A is a bifunctional monomer having amine groups. What is the name of monomer B?

• A. adipic acid
• B. ‚âà√¨‚àö¬¢-amino caproic acid
• C. undecanoic acid
• D. dodecyl lactam