The correct option is D thermocol
Fibre is a very thin, thread-like strand from which a material is made. It is categorized under two categories:
1. Natural fibres
2. Synthetic fibres
Nylon and polyester are examples of synthetic fibres and silk is a natural fibre obtained from cocoon of silkworm. Thermocol is not a thin, thread like strand. It is not a fibre.