The correct answer is (d) Triethylaluminium-titanium tetrachloride
Easy explanation: Dacron or terylene is a polyester of ethylene glycol and terephthalic acid. It is produced by heating the two at 420-460K and in the presence of zinc acetate-antimony trioxide, which acts as a catalyst. On the other hand, triethylaluminium-tetrachloride is used in the synthesis of HDPE.