The correct option is Plant fibre.
Explanation
Prehistoric rock paintings, particularly those from the Upper Paleolithic and Mesolithic periods (e.g., Bhimbetka in Madhya Pradesh), demonstrate the resourcefulness of early humans. Artists utilized naturally available materials to create pigments and tools suited for rough rock surfaces.
Analysis of Tools and Techniques:
- Plant fibre is Correct: Standard archaeological texts sources confirm that prehistoric artists typically made brushes from plant fibre. They would crush the tips of twigs or fibrous stems to create a bristled end, which was effective for applying pigments derived from minerals like haematite (red ochre) and limestone (white) onto stone walls.
- Animal hair is Incorrect: While animal products (like fat) were used as binders for the paint, the primary tool cited for application in Indian prehistoric art is plant fibre, not animal hair brushes, which are more characteristic of later, more refined artistic traditions.
- Metal wires is Incorrect: Prehistoric rock art largely predates the Metal Ages. The technology to manufacture metal wires did not exist during the periods when these paintings were created.
- Bird feathers is Incorrect: Bird feathers were not the typical tool for rock paintings, as the texture of the rock required a sturdier applicator like a crushed twig to effectively transfer the pigment.
Key Takeaway: Prehistoric artists relied on immediate natural resources, using mineral pigments mixed with water or animal fat for colour and plant fibres (crushed twigs) as brushes.