The correct option is C synthetic
Synthetic fibres are prepared from various chemicals. For example, nylon, acrylic, dacron, etc.
Natural fibres are obtained from plants and animals. For example, cotton (from seeds of cotton plant), and wool (from fleece of animals like yak, sheep, etc).
Semi-synthetic fibres are prepared by chemically treating naturally obtained substances. For example, rayon is prepared by chemically treating wood pulp.