The correct answer is option 1: Wool. Biodegradable waste refers to materials that can be broken down naturally by bacteria, fungi, or other biological processes. Wool is a natural fiber derived from animals like sheep, goats, and llamas. It is composed of proteins that can easily decompose over time.

Options 2, 3, and 4 (Polythene bags, Plastics, and Nylon) are not biodegradable wastes. They are synthetic materials made from polymers that do not break down easily in the environment. Polythene bags are made from polyethylene, which can take hundreds of years to degrade. Plastics and Nylon are made from petroleum-based materials and can persist in the environment for centuries.

Therefore, it is important to properly dispose of synthetic materials like polythene bags, plastics, and nylon to prevent environmental pollution.