Concept:Natural rubber is a polymer that can stretch and recover its original shape, classifying it as an elastomer.
Explanation:Natural rubber is made of isoprene units and has coiled, flexible chains.
These chains uncoil when stretched and recoil when the stretching force is removed.
This ability to undergo large reversible deformation is the defining property of elastomers.
Fibres, thermoplastics, and thermosetting plastics do not show this high elasticity.
Hence, natural rubber belongs to the elastomer class of polymers.
Answer:Option B – Elastomer