Final answer:
Crosslinking is the term used to describe the formation of covalent bonds between polymer chains. This is different from addition and condensation polymerizations, which are methods of creating the polymer chains themselves.
Step-by-step explanation:
The term used to describe the tying of adjacent polymer chains is B) Crosslinking. This process involves creating covalent bonds between polymer chains, which can significantly alter the physical properties of the resulting polymer material. While polymerization refers to the process where monomers join to form a polymer, and there are two types namely addition polymerization and condensation polymerization, crosslinking is specifically about linking chains after the polymer has been formed. In addition polymerization, all atoms of the starting monomers are retained. For example, ethylene molecules join to form long chains of polyethylene without the loss of any atoms. Conversely, condensation polymerization involves the loss of small molecules as byproducts, such as water, when forming polymers like polyamides.