Which one of the following is a plant fibre ?

Jute

The correct answer is Option (2) – Jute

The answer is: Option 2: Jute

Here's why:

Jute: This is a natural plant fiber commonly used to make burlap sacks, rope, and other textiles.
Wool: This is an animal fiber derived from sheep, goats, and other animals.
Polyester: This is a synthetic fiber derived from petroleum.
Silk: This is a natural protein fiber produced by silkworms. While it comes from a living creature, it's not a plant fiber.

Therefore, jute is the only plant fiber among the given options.