Which of the following statements accurately describe the mechanisms of polymerization? Select all that apply.

Polymerization can happen in two main ways: chain‑growth, where a reactive center keeps adding monomers one after another, and step‑growth, where large molecules link together gradually. In chain‑growth, the reaction starts with an initiator that creates a free radical, cation, or anion; each new monomer attaches to the growing chain, making the chain longer. In step‑growth, every monomer or oligomer can react with any other, so the chain length increases slowly as many small pieces combine. Coordination polymerization uses a metal catalyst to bind monomers and add them one by one, giving precise control over chain length and tacticity. Each mechanism relies on different types of reactive intermediates and dictates the final polymer’s structure and properties.