Which of the following are products of Agro Based Industry ?
1. Silk yarn
2. Cotton yarn
3. Polyfibre yarn
4. Polyester yarn
Select the correct answer using the code given below :

Agro-based industries are those that use plant and animal-based products as their raw materials. According to NCERT and official industrial classifications:

• Silk yarn: Produced through sericulture (rearing of silkworms), which depends on mulberry leaves. It is classified as an agro-based industry.
• Cotton yarn: Derived from cotton balls harvested from the cotton plant. It is a primary example of an agro-based textile industry.
• Polyfibre and Polyester yarn: These are synthetic or man-made fibers. They are derived from petrochemicals (chemicals obtained from petroleum or natural gas) and are therefore classified under the chemical-based or synthetic fiber industry, not agro-based.

Since only 1 and 2 are derived from agricultural/biological sources, option D is the correct answer.