Neoprene is produced by free-radical polymerization of 2-chlorobutadiene. In commercial production, this polymer is prepared by free radical emulsion polymerization. Polymerization is initiated using potassium persulfate. Bifunctional nucleophiles, metal oxides (e.g. zinc oxide), and thioureas are used to crosslink individual polymer strands. Outside of Russia and China,[why?] about 300,000 tons of neoprene are produced annually.
Ans : (c)