Which one of the following is one of the most resistant organic material known

Options

A. Pollen exine
B. Leaf cuticle
C. Cork
D. Wood fibre

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the most resistant organic material known. This requires knowledge of various organic materials and their properties.

2. **Identifying Organic Materials**: Consider common organic materials that are known for their resistance. Some examples include cellulose, lignin, chitin, and sporopollenin.

3. **Evaluating Resistance**: Among these materials, evaluate their resistance to environmental factors such as acids, alkalis, and temperature.

4. **Focusing on Sporopollenin**: Sporopollenin is a key organic material found in the outer layer of pollen grains (the exine). It is known for its exceptional resistance to degradation.

5. **Properties of Sporopollenin**: Sporopollenin is resistant to various environmental conditions, including extreme pH levels and temperature changes. This makes it one of the most durable organic substances.

6. **Conclusion**: Based on the evaluation, sporopollenin is identified as the most resistant organic material known.

7. **Final Answer**: The correct answer to the question is **sporopollenin**.