Polymerization is a process of producing:

Explanation

Polymerization is the process of chemically bonding monomers to form polymers, which are high molecular weight compounds. This transformation is crucial in producing materials like plastics and synthetic fibers. Option A is correct because it accurately describes this process. Option B is incorrect because the process does not produce low molecular weight compounds. Option C is incorrect as polymerization does not aim to produce intermediate molecular weight compounds. Option D is incorrect because polymerization involves forming polymers from monomers, not the other way around.