Given below are two statements, one is Assertion and other is Reason.
Assertion: Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties.
Reason: The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with coiled structure.
In the light of the above statements, choose the correct one from the options given below

We need to evaluate the Assertion and Reason about natural rubber. The Assertion states: "Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties." This is true because natural rubber is indeed cis-1,4-polyisoprene, a linear polymer of isoprene (2-methyl-1,3-butadiene) that exhibits elastic properties.

The Reason states: "The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with coiled structure." This is false since natural rubber is a non-polar hydrocarbon and its chains are held together by weak van der Waals forces rather than strong polar interactions. Although the cis configuration causes the chains to adopt a coiled structure, the intermolecular forces are not "strong polar interactions."

Since the Assertion is true and the Reason is false, the correct choice is: Assertion is true but Reason is false. Hence, the correct answer is Option C.