Out of chain growth polymerization and step growth polymerization,in which type will you place the following reaction: $-(A)_m + -(A)_n \to -(A)_{m+n}$?

(A) The given reaction represents chain growth polymerization. In this process,the polymer chain grows by the addition of monomer units to the active site without the loss of any small molecules like $H_2O$ or $CH_3OH$. The reaction $-(A)_m + -(A)_n \to -(A)_{m+n}$ indicates the simple addition of two chains or units,which is characteristic of chain growth polymerization.