Which one among the following groups of items contains only biodegradable items?

Biodegradable substances are materials capable of being decomposed by bacteria or other natural biological processes into simpler compounds. Option 2 (Wood, Grass, Leather) consists entirely of biodegradable items. Wood is a natural material derived from trees that microorganisms can break down [1]. Grass is organic plant matter that decomposes naturally in the environment. Leather, being an animal byproduct, is also biodegradable, although its rate depends on tanning processes. In contrast, other options contain non-biodegradable pollutants: Option 1 and 3 include plastics or synthetic materials like China clay (which is ceramic and does not decompose biologically), and Option 4 includes polystyrene, a petroleum-based plastic that persists in the environment for centuries [2]. While some modern bioplastics exist, conventional plastics and polystyrene are specifically classified as non-biodegradable pollutants [3].

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Glossary > p. 101
2. [2] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > 5.r.r. Classifications > p. 63
3. [3] https://www.sciencedirect.com/science/article/pii/S0964830524001586