Correct Option
The correct option is Plaster of Paris.
Explanation
Dhokra (or Dokra) is an ancient folk art tradition of non-ferrous metal casting known as the lost-wax casting (cire perdue) technique. This craft, practiced by tribal communities in states like Odisha, West Bengal, Chhattisgarh, and Jharkhand, relies entirely on indigenous, locally available natural materials.
Analysis of Materials
- Clay from ant hills (Correctly used): The core of the mold is traditionally made using fine clay, often collected from ant hills, because of its superior texture and binding properties.
- Cow dung and Rice husk (Correctly used): These organic materials are mixed with the clay to act as binding agents. They also provide porosity to the mold, allowing hot gases to escape during the casting process, which prevents the mold from cracking.
- Plaster of Paris (NOT traditionally used): This is a modern material used in industrial casting or contemporary sculpture. It is not part of the traditional Dhokra process, which strictly utilizes natural soil, wax, resin, and biomass.
Key Takeaway
Dhokra metal casting traditionally utilizes the lost-wax technique with natural raw materials such as beeswax, resin (damara), nut oil, ant-hill clay, and cow dung; it does not employ modern synthetic materials like Plaster of Paris.