Nylon was the first commercially successful synthetic thermoplastic polymer.
Terylene or Polyethylene terephthalate or polyester is for synthetic fibres.
A blend of wool and kevlar, the synthetic fibre widely used in body armour, was lighter, cheaper and worked better in damp conditions than kevlar alone.
Cotton is a soft, fluffy staple fibre that grows in a boll, or protective capsule, around the seeds of cotton plants.
The fibre is almost pure cellulose. so it is not synthetic.
Rayon is derived from natural cellulose and cannot be considered synthetic
PVC, Polythene, Bakelite all three are synthetic polymers.
Hence the correct option is C.