Which of the following is a natural fabric?
A.Polythene
B.PVC
C.Nylon
D.Wool

Hint: A fabric that is derived from naturally occurring substances is called a natural fabric. Any fibre that is derived from a naturally occurring substance is called a natural fibre. Sources of natural fibres can be plant based and animal based. Plant sources of natural fibres include cotton, jute, coconut, etc.

Complete step by step answer:
Animal sources of natural fibres include wool, silk, etc. Fabrics are made from fibres. Fabrics made from natural fibres are called natural fabrics.
Now, we consider each option.
In option A, Polythene is made from repeating units of a monomer called ethane. Since ethane is not a naturally occurring substance, polythene is not a natural fabric.
In option B, PVC stands for Poly Vinyl Chloride. It is made from a monomer called vinyl chloride. Since vinyl chloride is not a naturally occurring substance, PVC is not a natural fabric.
In option C, Nylon is made from chemical modifications of coal, water and air. Since it is not a naturally occurring substance, it can not be classified into natural fabrics.
In option D, wool comes directly from the sheep coat. Since the source is naturally occurring, it is a natural fabric.

Hence option D is correct.

Note:
Synthetic fibres have many advantages over synthetic fibres in terms of durability and strength. They include rayon, plastics, melamine, etc.
Natural fibres other than wool are silk (which comes from silkworm), jute (which comes from Hemp plant) and cotton (which comes from cotton plants).