Complex carbohydrates, especially fibre, are a form of carbohydrate. They are generally used to create clothing and paper. A fibrous substance called wood pulp is created by removing the cellulose fibres from wood.

The substances are polymers of several natural resources-obtained compounds. Some natural goods are obtained in their natural state, whereas others are obtained after being mechanically and chemically processed. Let's assess the possibilities and preparations that are presented.
A. Genuine silk. Fibroin makes up the majority of the fabric material in question. A protein fibre known as fibroin may be found in the cocoons of mulberry silkworm larvae. Silk is one of the strongest natural fibres and has strength.

 B. Rayon is produced or created from cellulose fibre that has undergone regeneration. To make rayon, wood pulp is utilised as the raw ingredient. It is created from filtered cellulose that has undergone chemical transformation into a complex soluble fibre molecule.
C. A condensation reaction between an acid monomer and an amine monomer produces the polymer nylon. This synthetic fibre is both durable and light. This sort of fibre is made without the use of any raw plant or animal components.

D. Polyethylene. Like its name would imply, it is a polymer compound. It is a byproduct of the condensation of an alcohol monomer and an acid. Multiple polyester bonds are produced by the acid and alcohol's repeating unit. Terephthalic acid and ethylene glycol are employed as the building blocks.

Hence, fiber obtained by chemical treatment of wood pulp is called rayon i.e. option B is the correct answer.