(c)
The process of condensation polymerization takes place in the following manner.
$\ \ \ \ \ \ A + B\ \ \ \ \ \overset{Condense\ \ \ \ \ }{\rightarrow}\ \ \ A - B$
Monomers dimer
$A - B + A\overset{Condense\ \ \ \ \ }{\rightarrow}A—B—A$
$A—B—A + B \longrightarrow \ A—B—A—B$
In this process no initiator is required and it is also called step growth polymerization.