15. POLYMERS (HM)
Explanation:
(c)\(\mathop {nC{H_3}}\limits_{{\text{Propene}}} - CH = C{H_2} \to \mathop {{{\rlap{-} ({\mkern 1mu} C{H_2} - \mathop {\mathop {CH{\text{ }}}\limits_{|{\kern 1pt} {\kern 1pt} \,\,\,\,\,\,\,{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} } }\limits_{C{H_{3\,\,\,\,\,\,}}} \rlap{-} )}_n}}\limits_{{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\text{Polypropylene}}} \)